Blackberry Yogurt Cake

Description
This is a recipe I obtained from an estate sale. I obtained it when I purchased the family collection from the Crawford Estate in Irving, Texas in 1982.
 * Contributed by Catsrecipes Y-Group

Ingredients

 * ½ cup blackberry yogurt
 * 2½ cups flour
 * 3 teaspoons baking powder
 * ¼ cup oil
 * ¾ cup granulated sugar
 * 1 teaspoon vanilla extract
 * 2 eggs
 * 1 cup blackberry preserves

Directions

 * 1) Mix all ingredients together except preserves and beat well until smooth.
 * 2) Pour into greased round cake pan and bake for 45 minutes.
 * 3) Heat preserves in saucepan stirring constantly until almost boiling.
 * 4) Remove from heat and cool 2 minutes then spread over cake.
 * 5) Cool before serving.