Pineapple who? No fruit here in this upside-down cake, just a brown sugary streusel-like layer of walnuts, coconut and granola baked under (then flipped over) a vanilla coffee cake.
Preheat oven to 350°. Place half of the butter in a 9-inch round cake pan. Place pan in oven for 5 minutes or until butter melts. Remove pan from oven. Add coconut, brown sugar, granola and walnuts; stir to mix thoroughly. Spread evenly in pan. Set aside.
In a medium bowl, stir together flour, baking soda and salt. Set aside. Melt remaining 1/3 cup butter; cool slightly.
In a large bowl, combine the melted butter, egg, granulated sugar, yogurt, orange zest and vanilla; stir until smooth. Stir in flour mixture just until combined. Gently spread batter over granola mixture in pan.
Bake for 30 minutes or until a toothpick inserted near center comes out clean. Cool in pan on a wire rack for 10 minutes. Loosen cake from sides of pan. Invert onto a serving plate. Replace any topping that sticks in pan. Serve warm or cool.