Prickly Pear Upside-down Cake

1/4 cup butter

1/2 cup brown sugar

3/4 cup whole wheat flour

3/4 cup unbleached all purpose flour

3/4 cup sugar

1 teaspoon baking powder

1/4 teaspoon salt

3/4 cup prickly pear juice

1/2 cup butter, melted

1 teaspoon vanilla

6 prickly pear fruit, glochids singed over fire, peeled, seeded and sliced

Preheat oven to 325 degrees F. In a 9 inch springform pan, put 1/4 cup butter. Put pan in the oven just until butter is melted. Sprinkle with brown sugar and arrange prickly pear fruit on top. Mix flours, sugar, baking powder and salt. Separately, mix prickly pear juice, 1/2 cup melted butter and vanilla. Combine the two mixtures and pour into prepared pan. Bake for 3o minutes or until a toothpick inserted in cake comes out clean. I like the cake to have some brown edges. Cool, invert on to a serving plate and enjoy.