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This Old Fashioned Rhubarb Crunch is a layered dessert made with tart, fresh-picked rhubarb, nestled between a buttery oat crisp topping. My vintage inspiration for this nostalgic dessert is straight from my grandmother’s handwritten recipe box. This easy rhubarb recipe is delicious when topped with a dollop of vanilla ice cream or homemade whipped cream and served at Spring brunch.🌸
If you are a rhubarb fan, be sure to try my Rhubarb Sourdough Muffins or Strawberry Rhubarb Pie Recipes!
Ingredients
Filling
- Rhubarb is hardy plant with edible stalks, harvested in the Spring, and known for its tart, sour taste.
- Sugar is a made by processing the juice of the sugarcane plant. Cane sugar is a natural option that is less processed with a slightly courser texture.
- Instant ClearJel is a modified food starch used as a thickener, stabilizer, and gelling agent. In baked goods it helps retain moisture and produces a light, tender texture.
- Vanilla provides hints of caramel and spice, enhancing the depth of flavor to baked goods. The best quality is an all-natural and made from real vanilla beans containing at least 35% alcohol.
Crunch
- All-purpose unbleached flour is made from ground wheat kernels with the bran and germ removed. It has a moderate protein content of 10-12%, making it a versatile option for most baked goods.
- Oats are a whole grain high in fiber and available as whole old-fashioned oats, or quick oats, which are finely cut and partially pre-cooked.
- Brown sugar is granulated sugar combined with molasses, sold as either light brown sugar (with 3.5% molasses) or dark brown sugar (with 6.5% molasses) for a more robust flavor.
- Cinnamon comes from dried bark from the tropical Asian cinnamon tree and is available as whole cinnamon sticks or ground. There are two types: Cassia which has a warm, sweet flavor, and Ceylon known as “true cinnamon”, which has an intense spicy bite.
- Pink salt is a type of rock salt found near the Himalayas, that is minimally processsed and contains trace minerals.
Baker’s Tips
- When making crumb topping, use soft, room temp butter since melted butter makes the crumb soggy.
- Aluminum baking pans that are light in color are best for conducting even heat. Use a 8″ or 9″ baking pan for thicker bars or 9×13″ glass pan for thin bars.
- Use cornstarch as a substitution if ClearJel is hard to find. For every 1 T. of cornstarch, use 1 1/2 T. ClearJel. For every 2 T. flour or tapioca, use 1 T. ClearJel. You can find it online here.
- If using frozen rhubarb, do not let it thaw, rather mix it into the boiled sugar mixture and pour on top of the bottom layer.
- This dessert is best when served the same day as the crisp topping may become soggy.
Dietary Substitutions
For the past 12+ years, I have owned an all-natural specialty bakery converting conventional recipes to gluten free, vegan, wholesome, etc. Read more about it here.
Here are a few basic tips when converting conventional recipes into specialty baked goods.
- Shelf Life: Specialty baked goods dry out faster and have a shorter shelf-life than conventional baked goods. Store in airtight container on counter a maximum of 1 – 2 days. The refrigerator will dry out baked goods, so it is best to freeze up to 6 months.
- Let Batter Rest: Alternate flours tend to be dense compared to white flour, so be sure to let the batter rest to help eliminate grittiness. Letting the batter sit 15 minutes to overnight will yield a light and tender baked good. For best results, refrigerate the batter overnight up to 3 days.
- Oven Temperature: Alternative flours are delicate and tend to brown faster before the center is cooked through, so reduce oven to 325° to bake low and slow adding a few minutes of bake time.
- Flour Hydration: Whole grain, almond, coconut, and oat flours can all yield dense baked goods. Add 1 – 2 tablespoons additional liquid (use the same liquid called for in the recipe).
Gluten-Free (no gluten)
- Flour: Swap out the flour with a premium gluten-free flour such as King Arthur Measure for Measure or use a homemade gluten-free flour blend. Be sure the flour blend contains xanthan gum. If not add 1/4 tsp. to 1/2 tsp. per every 1 cup of flour into the batter.
Vegan/Dairy Free (no animal products)
- Butter: Use unsalted vegan butter sticks such as Violife for best texture and flavor.
- Dairy: Replace the dairy with an unsweetened plant based milk such as oat, coconut or almond milk.
- Egg: To replace 1 egg, place 1 tsp. of baking soda into your batter then pour 1 T. white vinegar on top of the baking soda.
Keto (low carb, high fat)
- Flour: Swap out the white flour for almond flour or coconut flour.
- Sugar: Replace the sugar with monkfruit such as Lakanto Monkfruit Sweetener which mimics granulated sugar. Although the product suggests using a 1:1 swap, I find it too sweet and use a little less.
- Dairy: Replace the dairy with unsweetened plant-based milk (almond, flax or coconut).
- Hydration: Add 1 additional egg to the batter.
Wholesome (minimally processed)
- Flour: Swap out one third to half the white flour with King Arthur white whole wheat flour or King Arthur 100% whole wheat flour or use Bob’s oat flour.
- Sugar: Replace the sugar with maple syrup or honey. Use 3/4 c. honey for every 1 c. sugar called for in a recipe.
- Dairy: Replace the dairy with unsweetened plant-based milk (oat, coconut or almond).
- Fat: For every 1 c. of butter called for in a recipe, use 3/4 c. heart-healthy oil (extra-light olive) or 1/2 c. unsweetened applesauce + 1/2 c. oil.
Equipment
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How to pick and preserve fresh-picked rhubarb
- Pick rhubarb very early in the morning before the bugs are active and to avoid the sun.
- To refrigerate: put rhubarb stalks in an air-tight container and store in the fridge for 1 to 2 weeks.
- To freeze: place chopped rhubarb in a single layer on a 1/2 sheet pan lined with parchment paper. Freeze for 1 hour or until firm, and then place in ziploc bags or vacuum seal them for up to 1 year.
Rhubarb Crunch
Servings: 12
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Equipment
- 8" or 9" baking dish
Ingredients
CRISP
- 1 c. unbleached flour
- ¾ c. oats
- ½ c. brown sugar
- 1 ½ tsp. cinnamon
- ½ c. melted butter
FILLING
- 4 c. rhubarb diced
- 1 c. sugar
- 1 ½ T. instant ClearJel or cornstarch
- 1 c. water
- 2 tsp. vanilla
Instructions
PREP
- Dice the rhubarb in a separate bowl and set aside. Melt butter and set aside.
- Preheat the oven to 350°
BOTTOM LAYER
- In a mixing bowl put flour, oats, sugar and cinnamon. Pour melted butter over dry ingredients and mix together.
- Place 2/3 of the mixture into the bottom of the baking dish and press until smooth. (Save the remaining 1/3 for the top)
MIDDLE LAYER
- Spread chopped rhubarb all over the bottom layer.
- In a saucepan mix together the sugar, ClearJel, water, vanilla and cook until a thick and clear sauce. Pour over the rhubarb.
TOP LAYER
- Sprinkle the remaining 1/3 crumb mixture on top.
BAKE
- Top with the remainder 1/2 of the crumb mixture and bake at 350° for 1 hour.
- Serve warm with a scoop of ice cream or whip cream.
Related Recipes
More Rhubarb Recipes
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