1. Preheat oven to 400°F (200°C). Line a 9x13-inch (23x33 cm) baking pan with parchment paper leaving a 2-inch overhang on two sides.

2. In a medium bowl whisk granulated sugar for dough and brown sugar until combined. Add eggs and whisk until light and fluffy.

3. In a separate bowl whisk flour and baking powder.

4. Add softened butter to the flour mixture and cut in with a pastry blender until the mixture resembles coarse crumbs.

5. Pour the sugar-egg mixture into the flour-butter mixture and stir until just combined.

6. Stir in finely chopped almonds for dough.

7. Press the dough evenly into the bottom of the prepared pan.

8. Arrange plum halves cut-side up on the dough leaving a 1-inch (2.5 cm) border around the edges.

9. Sprinkle with granulated sugar for topping and sliced almonds for topping.

10. Bake for 30 to 35 minutes until the crust is golden brown and plums are bubbling.

11. Let cool completely in the pan on a wire rack. Lift out using the parchment overhang and cut into squares.