There is a cake in a glass casserole dish with a crumble topping. There is a knife in the casserole dish. There are some pieces missing. There is a slice of cake on a yellow floral plate. there is a scoop of vanilla ice cream on top. There are some pieces of rhubarb around on the table.

Grandma’s Secret Rhubarb Cake Recipe

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This easy old-fashioned rhubarb cake is a classic sweet, moist, cake that is a must in every vintage bakers repertoire. In late spring this is one of the first crops you can harvest from the garden.

There is a cake in a glass casserole dish with a crumble topping. There is a knife in the casserole dish. There are some pieces missing. There is a slice of cake on a yellow floral plate. there is a scoop of vanilla ice cream on top. There are some pieces of rhubarb around on the table.

Rhubarb is an easy and lovely plant to grow that comes back year after year. The tart stalks are perfect in desserts for a delicious balance of sweet and sour.

Storage

Rhubarb cake at room temperature

You can store rhubarb cake on the counter at room temperature for 3 days. Make sure to cover the cake so it stays fresh and moist!

If you still have cake leftover, it is best to move to a longer storage option.

Rhubarb cake in the fridge

Storing your rhubarb cake in the fridge is great for a little longer storage.

To keep your rhubarb cake fresh and moist, in the fridge, follow these simple instructions

  • Allow the cake to cool to room temperature
  • Cover the cake with plastic wrap or store in an airtight container
  • Store in the fridge for up to 7 days.

Rhubarb cake in the freezer

Rhubarb cake freezes extremely well. This is the best option for longer storage. To keep your cake soft, moist, and fresh follow these simple instructions

  • Allow the cake to cool to room temperature
  • Cover the cake completely in plastic wrap or airtight container
  • Store in the freezer for up to 3 months

When you are ready to use the cake, unwrap the cake and let it come back to room temperature. Slice and enjoy!

A woman holding a piece of rhubarb cake. There is more cake in the background

Can I bake with frozen rhubarb

Absolutely! Rhubarb freezes extremely well! You can either store your rhubarb whole or diced. Make sure to remove the leaves first before freezing. The leaves of the rhubarb plant are poisonous.

If you are using frozen whole rhubarb, cut it into a dice before it has fully thawed. It will be easier to cut partially frozen.

Before adding the frozen rhubarb to the cake, make sure to remove any excess moisture.

There is a slice of rhubarb cake on a yellow floral plate. There is a scoop of vanilla ice cream on top.

Perfect topping for my rhubarb cake

Crumble topping

This is my go to topping for this cake, which is why it is the one I included in the recipe! The sweet crispiness pairs perfectly with this soft, slightly tart, cake.

Cinnamon sugar topping

This is extremely easy to make! And the spiced sweetness just adds the perfect delicate crunch to the top of this soft, moist cake. To make a cinnamon sugar topping for your rhubarb cake

  1. To a small bowl, mix ¼ cup of brown sugar and 2 teaspoons of cinnamon.
  2. Sprinkle this mixture evenly overtop of the cake batter before baking.

Cream cheese icing

The sweet tanginess of this classic cream cheese icing takes this sweet treat to the next level of decadent dessert!

If you want to add this luscious cream cheese icing to your finished cake, check out this perfect cream cheese icing recipe!

Rhubarb cake on a yellow floral plate with vanilla ice cream on top. In the background is more of the cake. There is a spoonful of cake beside.

A little bit about rhubarb and why you need it in your garden!

Rhubarb is an amazing old-fashioned plant that is very commonly found in vintage gardens. It is an easy plant to grow and is one of the first plants we get a harvest from in our garden!

Not only is rhubarb a delicious edible plant, it is also a lovely leafy plant that looks beautiful in any garden. Meaning you don’t just have to plop it in the vegetable patch.

How to plant rhubarb

If you want to get started with rhubarb, it will take about 3 years to reach a mature size that you can harvest. It comes back every year as long as you harvest it correctly.

You can plant rhubarb using seeds in early spring in a sunny location. If you want to get a harvesting even sooner, buy rhubarb roots.

How to care for rhubarb

Rhubarb is a heavy feeder, so make sure to fertilize your plant 2 twice a year. Fertilize your plant once in early spring and then again in late summer. This will help your plant grown strong so you can enjoy a great a harvest year after year!

Make sure to plant in a sunny, well-draining location.

There is a rectangular casserole dish with a crisp top cake inside. Some slices have been removed. There is a slice on a yellow floral plate in front.

When to harvest your rhubarb

How do you know when to harvest your rhubarb? When you see that your plant has produced at least a dozen large leaves, your plant is mature enough to harvest and enjoy!

The actual stalk of the rhubarb should be about 12 inches (30 cm) long. Don’t harvest every stalk of rhubarb! Make sure to leave a few with leaves so they can continue to feed the roots and gather energy.

Once you see the flowers of your plant start to develop, it is time to stop harvesting. Cut the flower stalk off so the plant can put its energy into developing roots. This will ensure a stronger root system and a healthy plant for years to come.

There is a table full of ingredients they are labeled with arrows pointing to each.

How to make Grandma’s Secret Rhubarb Cake Recipe

Ingredients

Cake

1 ¼ cups all-purpose flour 187 g

¾ cup whole wheat flour 112 g

1 teaspoon baking powder 5 ml

½ teaspoon baking soda 2.5 ml

1 teaspoon cinnamon 5 ml

¼ teaspoon salt 1.75 ml

½ cup softened butter 115 g

1 egg

½ cup brown sugar 100 g

¼ cup white sugar 50 g

1 teaspoon vanilla 5 ml

1 cup buttermilk 250 ml

2 cups diced rhubarb (leaves removed) 2-3 stalks

Topping

½ cup brown sugar 100 g

2 teaspoons cinnamon 10 ml

½ quick oats 50 g

½ cup all-purpose flour 75 g

¼ cup cold butter 60 gd

Method

Cake

  1. Preheat oven to 350 ºF (180 ºC)
  2. In a medium bowl, mix the flours, baking powder, baking soda, salt, and cinnamon.
  3. In a large bowl, cream the butter with the white and brown sugar, until light and fluffy.
A glass bowl with flour, and cinnamon.
A metal bowl with creamed butter and sugar inside.

4. Beat in the egg and vanilla.

5. Alternating with the dry mixture and the buttermilk, beat in half of the dry mixture, then mix in half of the buttermilk. Continue with the last of the dry mixture and then mix in the last of the buttermilk.

6. Remove and discard the leaves from the rhubarb. Chop rhubarb into a small dice. You can use a food processor with the dice attachment disk or simply cut it by hand with a knife.

7. Stir in the diced rhubarb and pour into a greased cake pan or a large rectangular casserole dish.

    A woman using a food processor to cut rhubarb
    A woman mixing rhubarb into batter in a metal bowl.

    Topping

    1. Add the brown sugar, cinnamon, quick oats, and flour to a small bowl.
    2. Cut the butter into small cubes and rub it into the mixture, either with your finger tips or with a pastry blender.
    3. Sprinkle on top of the batter.
    4. Bake for 40-45 minutes or until a skewer inserted in the middle comes out clean.
    A cake batter in a glass casserole dish with an oatmeal crumble topping.
    A woman holding a pieces of cake. There is more in the background.
    Rhubarb cake on a yellow floral plate with vanilla ice cream on top. In the background is more of the cake. There is a spoonful of cake beside.
    Yield: 16

    Grandma's Secret Rhubarb Cake Recipe

    Prep Time: 15 minutes
    Cook Time: 45 minutes
    Total Time: 1 hour

    A sweet, moist, old-fashioned cake with dots of ruby red and tangy rhubarb throughout! A vintage recipe that is must bake at the beginning of summer when rhubarb is in abundance!

    Ingredients

    • CAKE
    • 1 ¼ cups all-purpose flour (187 g)
    • ¾ cup whole wheat flour (112 g)
    • 1 teaspoon baking powder (5 ml)
    • ½ teaspoon baking soda (2.5 ml)
    • 1 teaspoon cinnamon (5 ml)
    • ¼ teaspoon salt (1.75 ml)
    • ½ cup softened butter (115 g)
    • 1 egg
    • ½ cup brown sugar (100 g)
    • ¼ cup white sugar (50 g)
    • 1 teaspoon vanilla (5 ml)
    • 1 cup buttermilk (250 ml)
    • 2 cups diced rhubarb, leaves removed (2-3 stalks)
    • TOPPING
    • ½ cup brown sugar (100 g)
    • 2 teaspoons cinnamon (10 ml)
    • ½ quick oats (50 g)
    • ½ cup all-purpose flour (75 g)
    • ¼ cup cold butter (60 g)

    Instructions

    1. Preheat oven to 350 ºF (180 ºC)
    2. In a medium bowl, mix the flours, baking powder, baking soda, salt, and cinnamon.
    3. In a large bowl, cream the butter with the white and brown sugar until light and fluffy.
    4. Beat in the egg and vanilla.
    5. Alternating with the dry mixture and the buttermilk, beat in half of the dry mixture, then mix in half of the buttermilk. Continue with the last of the dry mixture and then mix in the last of the buttermilk.
    6. Remove and discard the leaves from the rhubarb. Chop the rhubarb into a small dice.
    7. Stir in the diced rhubarb and pour into a greased cake pan or a large rectangular casserole dish.

    TOPPING

    1. Add the brown sugar, cinnamon, quick oats, and flour to a small bowl.
    2. Cut the butter into small cubes and rub it into the mixture, either with your finger tips or with a pastry blender.
    3. Sprinkle on top of the batter.
    4. Bake for 40-45 minutes or until a skewer inserted in the middle comes out clean.

    Notes

    If you are using frozen whole rhubarb, cut it into a dice before it has fully thawed. It will be easier to cut partially frozen.

    Nutrition Information

    Yield

    16

    Serving Size

    1
    Amount Per Serving Calories 237Total Fat 10gSaturated Fat 6gTrans Fat 0gUnsaturated Fat 4gCholesterol 38mgSodium 223mgCarbohydrates 34gFiber 2gSugar 17gProtein 4g

    Did you try it?

    Let us know how it was!

    © flour and filigree
    Cuisine: American/Canadian / Category: dessert
    Looking for some more vintage desserts? Check out some of these classic recipes! Easy Retro Banana Caramel Pudding Cake, Elizabeth’s Fudgy Chocolate Pudding Cake, The Best Vintage Vanilla Cake
    A pinterest pin. In the picture is a cake with a crumble topping in a glass casserole dish. There are some pieces removed. There is a piece of the cake on a yellow floral cake. There are pieces of rhubarb in the background.

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    Hi, I'm Rebecca!
    I'm a Mom of 4 who is passionate about simple living, vintage whole food meals, and old-fashioned skills. Here on my blog, you will find comfort food recipes, delicious breads, and easy decadent desserts to share with your family, along with old-fashioned skills and simple living projects to make your home cozy.

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