INGREDIENTS
Cake
1 3/4 cups
cake flour
2 tsp
baking powder
1 tsp
salt
1/2 tsp
cinnamon
10
Tb unsalted butter, room temperature
3/4 cup
granulated sugar
1/2 cup
packed light brown sugar
3
eggs
1 cup
sour cream
Frosting
3/4 cup
plus 2 Tb granulated sugar
3 1/2
Tb cornstarch
2
Tb cocoa powder
3 oz
good quality unsweetened chocolate, coarsely chopped
6
Tb unsalted butter, cut into ½" pieces, at room temperature