Preheat oven to 350 degrees.
Grease an 8-inch round cake pan with softened butter. Dust with flour.
In a small bowl, combine flour, baking powder, and salt.
In a larger mixing bowl add eggs. Whisk with a hand-whisk until eggs are light and frothy.
Add sugar and whisk until just combined.
Add brandy and vanilla, and whisk until everything is incorporated and sugar is mostly dissolved.
Next pour in about half the flour mixture. Whisk until just incorporated.
Add half the melted butter and mix.
Repeat with remaining butter and flour.
Finally, add apple chunks and fold in gently with a spoon or spatula.
Bake for about 55-65 minutes or until toothpick inserted into center comes out clean, or with just a few moist crumbs.
Let cool, in the pan, on a baking rack.
Once cooled, slide a knife around the edges of the cake and invert to remove completely from the pan. Invert again so the cake is top-side up, and dust with confectioner's sugar before serving.