Go Back
–+ servings
4th of july cake recipes
Print

Blackberry Crisp Cake

Layers of fluffy vanilla cake swirled with blackberry purèe, topped with fresh blackberry buttercream and baked crisp topping throughout. It tastes just like blackberry crisp in cake form and is so perfect for summer!
Prep Time 1 hour 5 minutes
Cook Time 1 hour 5 minutes
Servings 15 slices

Ingredients

Blackberry Purèe

  • 2 Cups (453g) fresh or frozen blackberries
  • 1 Tbsp lemon zest
  • 1 Tbsp lemon juice
  • 2 Tbsp packed light brown sugar
  • 1 Tbsp cornstarch
  • 1/4 tsp ground cinnamon
  • 1/8 tsp salt

Blackberry Cake

  • 2 3/4 Cups (290g) sifted cake flour
  • 2 tsp baking powder
  • 1/2 tsp baking soda
  • 1/2 tsp salt
  • 3/4 Cup (170g) unsalted butter, room temperature
  • 1 1/2 Cups (300g) granulated sugar
  • 2 large eggs + 2 large egg whites, room temperature
  • 1/2 Cup (120g) sour cream, room temperature
  • 1 Tbsp pure vanilla extract
  • 1 Cup (240ml) whole milk, room temperature
  • 3/4 Cup (180ml) blackberry purèe, room temperature

Baked Crisp Topping

  • 1/2 Cup (40g) old-fashioned oats
  • 1/2 Cup (60g) all purpose flour
  • 1 1/2 Tbsp granulated sugar
  • 1/4 Cup (50g) packed light brown sugar
  • 1/2 tsp ground cinnamon
  • 1/4 tsp ground nutmeg
  • 1/8 tsp salt
  • 1/4 Cup (57g) unsalted butter, softened

Blackberry Buttercream

  • 2 Cups (452g) unsalted butter, room temperature
  • 7 Cups (840g) powdered sugar
  • 1 Tbsp pure vanilla extract
  • 1/2 Cup (120ml) blackberry purèe
  • 1/4 tsp salt, or to taste

Instructions

Make the Blackberry Purèe

  • Add the blackberries, lemon zest, lemon juice, brown sugar, cornstarch, cinnamon, and salt into a medium saucepan. Cook over high heat until the mixture begins to boil, then use a fork to mash up the berries. Continue to cook for 10-15 minutes or until the purèe has thickened and reduced by about 1/3. You should have around 1 ¼ Cups of blackberry purèe after the reduction. Remove from the heat and place into an airtight container in the refrigerator to let cool for about 30 minutes, or until room temperature. It will thicken as it cools.

Make the Blackberry Cake

  • Preheat the oven to 350°F. Prepare three 6-inch or two 8-inch cake pans by spraying the sides with a cooking spray (Baker's Joy is my favorite) and fitting a parchment paper circle to the bottom of the pan.
  • Sift the cake flour and then measure by spooning and leveling it in your measuring cup. Add the cake flour, baking powder, baking soda, and salt into a bowl and whisk to combine. Set aside. 
  • In the bowl of your stand mixer (a handheld mixer works fine too!), beat the butter on high for two minutes until it's light and creamy. Add in the sugar and continue to mix on medium-high for another two minutes. Turn the mixer to low and add the eggs and egg whites, one at a time, mixing until just combined and scraping down the bowl and paddle as needed. Add the vanilla and sour cream, turn the mixer to high, and beat for one full minute. It will look curdled at this point, but don’t worry – it will become smooth cake batter at the end.
  • Add in the dry ingredients all at once and turn the mixer to low speed. Mix until just combined, then slowly pour in the milk. Continue to mix on low speed until just combined, about 30 seconds. Scrape down the sides and bottom of the bowl and give it a few stirs with a whisk to make sure there are no lumps. The batter will be slightly thick.
  • Pour the batter evenly into the prepared cake pans. Dollop the blackberry purèe by the spoonful on top of each cake and use a butter knife to swirl it into the batter, then bake for 30-35 minutes. They're done when they spring back to the touch and a toothpick inserted into the middle comes out clean. Let the cakes cool in the pan for five minutes before turning them out onto a wire rack for an additional few hours of cooling. Make sure they're entirely room temperature before applying any frosting. 

Make the Baked Crisp Topping

  • Preheat the oven to 350 degrees and line a cookie sheet with parchment paper. Add all of the ingredients except for the butter into the bowl of a stand mixer fitted with the paddle attachment. Mix together on low to combine, then add in the softened butter. Continue mixing on low until the mixture begins forming pea-sized clusters.
  • Spread the mixture evenly onto the parchment-lined cookie sheet, then bake for 5 minutes. Stir the topping around a bit, then bake for another 5 minutes until it begins to turn golden brown. Let the crumble topping cool completely to room temperature, then store in an airtight container until you’re ready to assemble the cake.

Make the Blackberry Buttercream

  • In the bowl of a stand mixer fitted with the paddle attachment, cream the butter on medium-high until it’s creamy and light in color, about 5 minutes. Turn the mixer to low and add the powdered sugar a few cups at a time, scraping down the bowl and paddle after each addition and making sure each cup is fully incorporated before adding the next one. 
  • Add the vanilla, blackberry purèe, and salt and mix on low for another 1-2 minutes, or until fully incorporated. 

Assembly

  • Once the blackberry cakes are completely cooled, level them to your desired height. Add a swipe of blackberry buttercream onto a cardboard cake circle and place the first layer on top. Add a layer of blackberry buttercream as filling, then sprinkle on about 1/4 Cup of baked crisp topping before adding the next layer on top. Repeat the filling and stacking process with the final cake layer. Crumb coat the cake with blackberry buttercream, then place it in the refrigerator for at least 30 minutes to let the buttercream set firm.
  • Create a smooth buttercream finish with blackberry buttercream, then press baked crisp topping onto the bottom third of the cake. Use Wilton Tip 4B to pipe swirls with blackberry buttercream around the top edge of the cake (you may need to thicken the buttercream consistency for this part). Top each buttercream swirl with a fresh blackberry and sprinkle more baked crisp topping on top.

Notes

Make Ahead Tips: 
  1. The blackberry purèe can be made ahead and stored in an airtight container in the refrigerator for up to two days. Bring it back to room temperature before using it in the cake and buttercream recipes. 
  2. The blackberry cake can be baked ahead and stored at room temperature, wrapped in plastic wrap, for up to two days. Alternatively you can store the cakes in the freezer for up to two months.  
  3. The baked crisp topping can be stored in an airtight container in the refrigerator for up to two weeks. 
  4. The blackberry buttercream can be made ahead and stored in an airtight container in the refrigerator for up to two weeks. When you’re ready to use it, bring it back to room temperature and re-mix in your stand mixer to bring it back to smooth buttercream consistency.