Grease a 9" springform pan with butter and dust with flour
Beat the butter and sugar in the bowl of your stand mixer with the paddle attachment until light and fluffy, around 3 minutes
Add the eggs to the butter mixture one at a time. Beat the mixture well and fully incorporate each egg before adding the next.
In a separate bowl, whisk the flour, baking powder and salt.
Add the flour mixture to the butter mixture to form a thick batter.
Assembly and Baking
Stir the sugar and cinnamon and set aside
Transfer the batter to the prepared springform pan. Top with fruit and dust with the cinnamon sugar.
Bake for 70 minutes or until the cake is evenly domed and springs back in the middle. Check cake after 1 hour as it may cook quickly depending on the fruit used.
Transfer to a wire rack to cool. Remove the sides when cool enough to handle.
Let cool further until just warm to the touch. Sprinkle with powdered sugar, slice and serve.