Steps
- Preheat the oven to 350°F / 175°C. Grease three 8in / 20cm round cake pans, line their bases with parchment, and grease the parchment. Measure 1 cup of softened unsalted butter and reserve half for the frosting.
- Beat the remaining butter on high for 1 minute. Add 1¼ cups of granulated sugar and ½ cup of packed light brown sugar, then beat on medium-high for 2 minutes.
- Beat in ¼ cup plus 2 tablespoons of vegetable oil for 3 minutes. Add 4 large room-temperature eggs and 1 tablespoon of vanilla extract, then beat on medium for 1 minute, scraping down the bowl.
- Whisk 3 cups of all-purpose flour, 2 teaspoons of baking powder, ½ teaspoon of baking soda, and ½ teaspoon of salt together. Briefly beat into the batter on low speed.
- Mix in ¾ cup of room-temperature buttermilk, 2 tablespoons of lemon zest, and ½ cup of room-temperature lemon juice just until combined. Toss 1½ cups of fresh blueberries with 1 tablespoon of all-purpose flour and gently fold in.
- Divide among the pans and bake for 22-26 minutes, until a toothpick inserted in the center comes out clean. Cool completely in the pans.
- For the frosting, beat 226g of softened full-fat brick cream cheese with the reserved butter on medium for 3 minutes.
- On low, mix in 3½ cups of confectioners' sugar, 1 tablespoon of heavy cream, 1 teaspoon of vanilla extract, and a pinch of salt, then beat on high for 3 minutes.
- Unmold the cakes and trim their tops level. Stack with frosting between the layers, then spread the remaining frosting over the top and sides.
- Refrigerate for at least 45 minutes before slicing.