Yield: 9-inch round cake
Combine flour, almonds, sugar, and salt in a food processor. Pulse until almonds are ground. Transfer to a large mixing bowl. Using a pastry blender or fork, cut the butter into the flour until mixture resembles coarse sand. Add milk and yolk. Fold to combine until dough comes together.
Place dough into into a 9-inch round springform pan. Press dough into the bottom of the pan and about 1/2-inch up the sides. Cover with plastic wrap and let chill in the freezer for 20 minutes until cold. Alternatively, chill in the fridge for 1 hour up to 24 hours.
Preheat oven to 375 degrees F. Use a fork to dock the crust all over. Bake for 20-25 minutes until crust is golden. If crust bubbles during baking, simply press down with the flat bottom of a drinking glass.
Remove from oven and allow crust to cool on wire rack while you prepare crumble and filling.
Place flour, almond paste, brown sugar, and half of chopped almonds in food processor. Pulse until mixture is thoroughly combined. Transfer to a bowl. Using a fork (or your fingers), cut butter into the mixture until coarse crumbs form. Fold in chopped almonds.
Toss together plums, sugar, cornstarch, and salt.
Sprinkle about 1/2 cup of crumble over cooled crust. Arrange plum filling on top. Distribute remaining crumble over plums.
Place springform pan on top of a baking sheet. Filling may slightly leak. Bake for 40-45 minutes until the crumble is golden brown. Allow cake to cool in pan for 15 minutes before unmolding. Release from springform pan and allow to cool on wire rack. Allow cake to cool for at least 20 minutes before slicing into. Enjoy cake warm or at room temperature.
recipe adapted and inspired by this plum tart with marzipan crumble