Preheat your oven to 350°F (175°C) and lightly grease a 9-inch round springform pan.

In a large mixing bowl, beat the softened butter and granulated sugar together until pale and creamy, then mix in the egg yolks one at a time.

Sift in the flour, baking powder, and ground cardamom, mixing until a soft, cohesive dough forms.

Wrap the dough in plastic wrap and refrigerate for about 20 minutes to make it easier to handle.

While the dough chills, prepare the filling by combining the ground almonds, powdered sugar, egg whites, and orange zest in a bowl; stir until a thick, sticky paste forms.

Remove the dough from the fridge. Press approximately two-thirds of the dough evenly into the bottom and slightly up the sides of the prepared pan.

Spread the almond and orange filling evenly over the dough base using a spatula.

Roll out the remaining one-third of the dough on a floured surface and cut into strips. Arrange these strips in a lattice pattern over the filling.

Brush the lattice strips gently with the beaten egg to create a glossy, golden finish.

Bake in the center of the oven for 35 to 40 minutes, or until the crust is golden brown.

Allow the cake to cool completely in the pan before removing the ring and slicing, as the filling needs time to set.