Caramel Apple Upside Down Cake Recipe

Preheat oven, grease pan.

Place 1/2 cup brown sugar in small bowl; cut in 3 tablespoons butter until crumbly. Stir in sunflower nuts. Press onto bottom of prepared pan. Arrange apple slices on top. Set aside.
Combine flour, baking powder and salt in medium bowl. Combine 2/3 cup brown sugar and 1/3 cup butter in mixer bowl. Beat at medium speed, scraping bowl often, until creamy (1 to 2 minutes). Add egg and vanilla; continue beating until smooth (1 to 2 minutes). Add flour mixture alternately with milk until well mixed (1 to 2 minutes).
Spoon batter over apple layer; spread evenly. Bake until toothpick inserted in center comes out clean. Cool 5 minutes; invert onto serving plate. Serve warm or cool.