Apple Coffee Cake

Cake Ingredients:
...
½ cup butter
¾ cup sugar
2 eggs, lightly beaten
1 teaspoon vanilla extract
1½ cups flour
¾ cup vanilla yogurt

Topping Ingredients:

1 Granny Smith Apple, peeled, cored, and thinly sliced
½ cup sugar
1½ teaspoons ground cinnamon
2½ tablespoons butter

Directions:

1. Grease 10-inch round spring form pan and line bottom with wax paper.
2. Beat butter and sugar until light and creamy.
3. Gradually add beaten eggs, one at a time, beating well after each one.
4. Fold in flour.
5. Fold in yogurt, stirring until smooth.
6. Spoon batter into prepared pan and smooth out surface.
7. Arrange apple slices evenly over mixture in a circular pattern, starting in center.
8. Mix the cinnamon and sugar together, and sprinkle over the apples.
9. Melt butter, and drizzle over apples, cinnamon and sugar.
10. Add Extender Ring to Pro base. (Nu Wave oven)
11. Place pan on 2-inch rack and bake on Power Level 8 for 1 hour.
12. Set pan on wire rack to cool for 30 minutes before unmolding.