Classic German Berliner donuts are soft, fluffy, and pillowy fried dough balls filled with luscious raspberry jam and coated in a mix of cinnamon sugar and powdered sugar. This recipe uses a simple yeast dough enriched with egg yolks, butter, and lemon zest for a delicate flavor and texture. The dough is fried until golden, then filled and coated, making a perfect treat to enjoy fresh and warm.