1-1/2 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon cardamom
1/4 teaspoon salt
1 cup butter, room temperature
1 cup sugar
1 teaspoon vanilla
3 egg yolks (or 2 large eggs)
1 Tablespoon sugar
1/2 teaspoon cinnamon
Line a 9-1/2" springform pan with wax paper. Preheat oven to 350 deg. F.
Mix flour with baking powder, salt and cardamom. Set aside.
Whip softened butter and 1 cup sugar in mixer until light and fluffy. Mix in the vanilla. Add eggs, one at a time, beating well after each one. Add the dry ingredients and mix.
Spread batter into pan. Slice the plums into eight pieces and layer into the cake batter. Mix the tablespoon sugar with cinnamon and sprinkle over plums.
Bake about one hour until cake is golden and cake tester or toothpick comes out clean.