1. Place a rack in the upper-middle of oven and heat to 400 degrees.
2. Whisk flour, baking powder, cinnamon, and salt in a medium bowl. In another bowl, whisk milk, egg, sugar, 2 tablespoons butter, and vanilla. Add wet ingredients and apple to flour mixture and stir until just combined.
3. Heat remaining 2 tablespoons butter in a medium oven-safe nonstick skillet over medium heat, swirling pan to coat. When butter is hot, evenly sprinkle brown sugar over the skillet and pour in batter. Smooth top and bake until golden brown and cooked through, about 20 minutes.
4. Let cake cool in the skillet for 10 minutes, then carefully invert it onto a serving plate. Top with confectioner's sugar and whipped cream (if using) and serve.
Source: Hannaford fresh Magazine, March - April 2016