113g.unsalted butter, at room temperature(8 tbsp. or one stick)
Small pinchsalt
1tsp.vanilla extract
218g.confectioner’s sugar(1¾ cups)
Instructions
Cake. Preheat oven to 350° Lightly grease one 8-inch round pan, line it with parchment circle on the bottom and grease the top of the parchment. In a large bowl, whisk together all the dry ingredients through the dark brown sugar. Whisk in oil, eggs and vanilla until combined. Whisk in milk and sour cream until combined. Pour into prepared pans and bake 35-40 minutes, until a toothpick inserted comes out clean and the sides are just starting to pull away from the pans. Cool completely in pans.
Blueberry Frosting. Using the paddle attachment of the mixer, beat the Blueberry Paste and butter together for a minute or two until fully combined and the mixture is lightly aerated. Add the salt and vanilla extract, beating until combined. Stop the mixer and pour in confectioner’s sugar. Start with the mixer on the lowest speed, raising it as the confectioner’s sugar gets incorporated into the mixture. Beat on high for a minute or two. (If the frosting seems too thick, add a teaspoon or two of milk or heavy cream.)
Assembly. Slide a metal spatula or knife around the edges of the cake pan. If the cake has domed in the middle, use a serrated knife to cut the dome so the cake is even. Frost the top and sides of the cake as desired.
Storage. The cake can be stored in an airtight container at room temperature, but it will keep longer stored in the refrigerator, allowing it to come to room temperature approximately 30 minutes before serving.
Notes
For a more evenly baked cake layer (no doming), use a cake strip. I cannot recommend these enough! You just wet the strip and wrap it around the base of the baking pan just before putting the pan in the oven. It prevents the edges from baking too much faster than the center of the cake, resulting in a more even bake and little to no doming in the center.
You can absolutely use a 9-inch round pan. The baking time will be less, so I recommend to start checking it after 25 minutes.