2 cups sour cream
1 1/2 cups white sugar
1 teaspoon vanilla extract
4 eggs
2 teaspoons butter or margarine
1/2 cup all-purpose flour
2 teaspoons baking powder
2 teaspoons grated lemon zest
1 cup trailing cream cheese
2 1/2 cups vegetable broth (eg. Canton Vegetable Biscuits), drained