About half an hour before you start baking, take out eggs, milk, and heavy cream from the fridge to bring them to room temperature.
Grease a baking sheet and dust it with breadcrumbs.
Prepare pitted plums, cut them into small pieces.
Preheat the oven to 340 °F (170 °C).
Make streusel topping:
Cut cold butter into flour, add sugar, and ground cinnamon. Using your fingertips, work everything into a crumbly mass.
Let’s bake:
Combine plain flour and baking powder in a large mixing bowl. Add sugar, heavy cream, milk, lemon zest, and eggs. Start stirring with a fork, then use a hand-held mixer and mix on a lower speed until a semi-liquid batter is created.
Pour the batter into a dusted baking sheet. Put the plums regularly over the entire surface of the cake.
Sprinkle with the streusel topping as the final step.
Bake the streusel cake for 30 minutes until the surface is golden brown.
Notes
Let the sheet cake cool down, then cut into regular rectangles and serve on a dessert plate as a coffee cake. You can also dust the cake with powdered sugar before serving.
Makes about 25 pieces.
Plums are not a necessity in this streusel cake. If you don't have plums, other fruits are also suitable, for example, raspberries, strawberries, or grated apples.
The amount of batter in this recipe fits a rectangular baking pan measuring approximately 12x14 inches (30x35 cm). The cake is relatively thin but moist. If you want a higher layer of batter, use a smaller-sized baking pan.