Pulse the walnuts in your food processor until fine meal.

Beat 7 oz. of the butter with the light brown sugar until creamy.

Add eggs, one at a time and incorporate each one, before you add the next.

Mix baking powder and flour. Add flour mixture and walnuts to butter-egg mixture, as well as the vanilla extract and mix until smooth.

Peel and core the apple. Cut in quarters and slice thinly, but keep the slices together.

Pour the batter in the cake form and level the top. Place apple quarters on top of the cake and push them into the batter.

Melt 1 oz. of butter and pour this over the apple pieces. Sprinkle with 1 tablespoon of sugar.

Place cake in the over and bake for approx. 1 hour.