INGREDIENTS
2
Eggs plus, large
1 cup
Blueberry jam, store-bought
1/2 tsp
Baking soda
2/3 cup
Brown sugar, packed dark
6 cups
Cake flour
1 1/2 tsp
Cinnamon, ground
1
Confectioners' sugar
1 2/3 cups
Granulated sugar
2
Salt, Coarse
1 tsp
Vanilla extract, pure
4 sticks
Butter, unsalted
2/3 cup
Buttermilk, low-fat