INGREDIENTS
4 cups
all-purpose flour (see notes)
3 tsp
baking powder
1/2 tsp
cream of tartar
1/2 tsp
kosher salt
1 cup
unsalted butter, softened
2 cups
granulated sugar
2 cups
full fat sour cream
3/4 cup
milk (I used 2%)
2 tsp
pure vanilla extract
2 cups
confectioners' sugar
3 tbsp
(45-60ml) milk