INGREDIENTS
1 tsp
Lemon, zest
1 5/8 lb
Rhubarb
3
Eggs, large
1 1/4 tsp
Baking powder
1/4 cup
Brown sugar, light
3 cups
Flour
1 1/4 tsp
Salt, coarse
2 cups
Sugar
1 tsp
Vanilla extract, pure
1
Vegetable-oil cooking spray
2 sticks
Butter, unsalted
1/2 cup
Sour cream