– 3 ½ cups All-purpose flour – 2 teaspoon Baking powder – 1 teaspoon Baking soda – 1 teaspoon Salt – ¾ cup Unsalted butter room temperature – ¼ cup Oil canola or vegetable oil – 1 ½ cups White granulated sugar – 3 Large lemons zested – ¼ cup Lemon juice freshly squeezed – ¼ cup Sour cream room temperature – 4 Large eggs room temperature – 1 cup Buttermilk room temperature – 3 cups Fresh or frozen blackberrie – ¾ cup White granulated sugar – 1 tablespoon Lemon juice – ⅛ teaspoon Salt – 1 ½ cups Unsalted butter slightly cold – 8 oz Cream cheese room temperature – 7 cups Powdered sugar sifted – Zest of 1 lemon – ¼ cup Lemon juice freshly squeezed – ½ teaspoon Salt
Heat the oven to 350°F. Spray three 8-inch cake pans with nonstick baking spray. Spray again after lining cake pans with 8-inch parchment circles.Sift flour in a basin. Mix in baking powder, soda, and salt. Set aside.
1
Mix butter, oil, and sugar for 3 minutes on high. Creamy and almost white. Combine sour cream, lemon zest, and juice. Beat medium to combine. Bowl scrape.Add eggs one by one. Beat high 2 minutes. It's natural to appear split.
2
Mix ⅓ dry ingredients and half buttermilk on low. Stir in another ⅓ of the dry ingredients and the remaining buttermilk. Finish using dry ingredients. Simply combine.Pour batter into three pans. Bake 18-22 minutes.
3
Let cakes rest in heated pans for 10 minutes. Transfer to a cooling rack. Cool fully.Add blackberries, sugar, lemon juice, and salt to a medium saucepan over medium-high heat. Stir until berries soften and liquid releases.
4
Softly mash berries over medium heat. Cook jam 5-8 minutes until thick.Put jam in a glass measuring cup. Cool completely.Let butter sit for 30 minutes. While you wait, sift powdered sugar into a large dish. Use a small bowl to zest the lemon.
5
Mix butter and cream cheese on high for 2 minutes. Scrape basin and gently add powdered sugar. Very thick.Add salt, lemon zest, and juice. Mix low until mixed. Use high speed to beat until fluffy, 1-2 minutes.
6
Spread a little frosting on your decorating board. Trim domes on cakes with a sharp knife until even.Place the first cake layer on the board. Apply ¾ cup of icing on the cake. Frost the cake edges with icing. Spread half the jam on the cake.
7
Repeat with cake layers 2 and 3. Cover the cake with light icing. Cake crumbs are locked in by freezing for 15 minutes.Finish frosting the cake. Add lemons and blackberries.
8