Ingredient

Substitute

Baking powder

For 1 tsp., use 1/2 tsp. cream of tartar plus 1/4 tsp. baking soda

Buttermilk

For 1 cup, use 1 Tbsp. lemon juice or vinegar plus enough milk to make 1 cup; let stand 5 minutes before using

Cake flour

For 1 cup, use 1 cup minus 2 Tbsp. all-purpose flour

Cornstarch (for thickening)

For 1 Tbsp., use 2 Tbsp. all-purpose flour

Dairy sour cream

For 1 cup, use 1 cup plain yogurt

Egg

For 1 whole egg, use 2 egg whites, or 2 egg yolks, or 1/4 cup egg product

Granulated sugar

For 1 cup, use 1 cup packed brown sugar, or 2 cups stirred powdered sugar