Lemon Blueberry Layer Cake

unsalted butter, softened to room temperature

and 1/4 cups (250g) granulated sugar

packed light brown sugar

large eggs, at room temperature1

vanilla extract

sifted all-purpose flour, (spoon & leveled)2

baking powder

salt

buttermilk3

zest + juice of 3 medium lemons4

and 1/2 cups blueberries, fresh (258g) or frozen (do not thaw-- 275g)

all-purpose flour

full-fat brick style cream cheese, softened to room temperature5

unsalted butter, softened to room temperature

and 1/2 cups (420g) confectioners' sugar

(15-30ml) heavy cream6

vanilla extract

salt