Blueberry Shortbread Crumble Cake Recipe

Directions

For the Blueberry Cake with Shortbread Crust

Preheat the oven to 325°F, then prep three 6-inch round cake pans with a swipe of shortening and dusting of flour to prevent sticking. In a food processor, pulse together the shortbread cookies and melted butter until a fine crust forms. Reserve 2/3 cup of the shortbread crumble and set aside. Split the rest of the crust mixture evenly among the prepared pans and press to firm with the bottom of a glass or flat measuring cup. In a large bowl, whisk together the buttermilk, sour cream, blueberry puree, eggs, oil, vanilla and blueberry emulsion until thoroughly combined. Sift the cake mix into the mixture and whisk until just combined. Do not overmix. Split the batter evenly among the prepared pans. Bake for 32 to 35 minutes, until the center is baked through. Let the cakes cool in the pan for a minute before flipping them out onto a wire rack to cool completely. Wrap and freeze the cakes before assembly.

For the Blueberry Filling

In a small saucepan over medium heat, stir together the blueberries, sugar and lemon juice and cook, stirring, until thick and bubbly, about 5 minutes. Sift the cornstarch into the mixture and stir until thickened, 2 to 3 minutes. Transfer the filling to a bowl, cover and refrigerate until thickened and cooled completely.

For the Blueberry Buttercream

In the bowl of a stand mixer fitted with a paddle attachment, beat the butter on medium speed until it’s light and fluffy. Add the heavy cream, blueberry emulsion, vanilla and salt and beat again until combined, then scrape down the sides with a spatula. With the mixer on low speed, add the powdered sugar about ½ cup at a time. The buttercream will be thick. Add a little more heavy cream, 1 tablespoon at a time, to thin it out if needed, and then flip the mixer to high speed and beat until the buttercream is lighter in color and texture, about 2 minutes.

For the Shortbread Crumble

Preheat the oven to 350°F. Spread out the reserved crumble on a cookie sheet lined with parchment paper. Bake for 7 to 10 minutes, until toasted and golden. Set aside to cool completely before adding to the cake.

To Assemble

Place a cardboard cake round on a cake turntable. Dot a little bit of buttercream in the center of the round and spread it out with an angled icing spatula. Place the first chilled cake layer in the center (crust side up). Add a thin layer of buttercream. Pipe a buttercream dam around the outside rim of the frosted cake layer, then add about ½ cup of the blueberry filling. Place the next cake layer on top, then repeat, making sure to line the layers up evenly. After adding the top cake layer, crumb coat the cake by spreading a thin layer of buttercream around the entire cake. Freeze for 2 minutes to set the buttercream. Using a wooden spoon, beat out any air bubbles in the remaining buttercream. Finish frosting the cake as desired or follow the decorating instructions below.

To Decorate the Cake

Spread a final layer of buttercream around the entire cake, using a cake scraper for smooth sides. Leave the top edge uneven for a rustic look. Press the blueberries in groups of three into the buttercream and add one leaf per trio. Sprinkle the reserved baked crumble over the top.

Tip: When decorating a cake with fresh leaves, make sure to research what is cake-safe, wash and dry the leaves thoroughly and remind your guests that they’re just for garnish. I used blueberry leaves from our blueberry plant in the garden, and they looked cute as a button next to the trio of blueberries pressed into the side of the cake.

Bake With Mandy

Harvest

Two more recipes from I’ll Bring the Cake for AARP members to try:

Chocolate Peanut Butter Cake

Stripes of thick whipped peanut butter and cocoa buttercreams envelop this chocolate cake.

Circus Animal Cookie Cake With Almond White Chocolate Buttercream

This cake, with a strong almond and white chocolate flavor throughout and pink and white exterior, tastes and looks just like circus animal cookies. 

Read About Mandy Merriman’s cookbook, I’ll Bring the Cake.