Butter and flour an 8" or 9" springform pan, or for a rustic look opt for a 8x8" square baking dish. Preheat the oven to 350° F.
In a large bowl, cream the butter and sugar until they lighten in color, about 3 minutes. You can do this with a danish dough whisk if you don't have an electric mixer.
Add the eggs, one at a time, beating about a minute after each incorporation. If you're using an extract, add it here.
Add in the flour, baking powder, and salt and mix on low until combined.
Spread the batter into the pan.
Arrange the fruit as you wish on top of the batter.
Squeeze the juice of a lemon over the fruit and sprinkle with sugar and cinnamon.
Bake about 40-50 minutes, or until a cake tester or toothpick inserted into the middle comes out clean.
Run a knife around the edges between the cake and the pan to loosen it from the sides.
Remove the sides of the pan and let the cake cool 20 minutes on a wire wrack before transferring to a serving plate, or keeping the bottom of the pan on to serve. If you're using a 8x8" pan, don't even worry about this step, just let it cool in the pan, on the counter.
Before serving, sprinkle with powdered sugar.
The cake freezes very well after fulling cooling wrap well in plastic wrap. To defrost, bake at 300° F for about 10 mins.
