01 -
Work the flour, sugar, vanilla sugar, baking powder, cocoa, butter, and sour cream into a shaggy dough, just until it holds together. Wrap it and chill for 2-3 hours, or freeze for about 40 minutes, until firm enough to grate.
02 -
Grease a 13x9-inch (33x23 cm) pan. Coarsely grate about three quarters of the chilled dough across the bottom and press it into an even layer with your fingers.
03 -
Beat the eggs with the sugar and vanilla sugar until pale and roughly doubled in volume. Stream in the cooled melted butter, then fold in the ground cheese and pudding powder by hand until smooth.
04 -
Spread half the cheese filling over the base. Scatter the drained, sliced peaches evenly across it, then spoon the rest of the filling on top and smooth the surface.
05 -
Coarsely grate the remaining chilled dough directly over the filling so it lands in loose, even crumbs rather than one solid sheet.
06 -
Bake at 340°F (170°C) for 65-75 minutes, until the crumble looks dry and the center only jiggles slightly when the pan is nudged.
07 -
Let the cake cool completely in the pan, then refrigerate at least 4 hours, ideally overnight, so the layers set into clean slices.