1/2 c. powdered sugar
1 cube unsalted butter
1/2 tsp vanilla extract
1 1/4 c. all-purpose flour
1/4 tsp. salt
1/2 egg, beaten
zest of 1/2 lemon
Preheat the oven to 350F.
Blend the sugar and butter on low speed until a smooth paste forms. Add the egg and vanilla. Add the flour, salt, and lemon zest and continue to mix on low speed just until the dough comes together. Remove from the bowl, form into a disc, and wrap tightly in plastic wrap. Allow the dough to chill in the refrigerator for at least an hour before using.
Press the chilled dough into a 9″ tart pan. Chill again, just until firm. Line the pan with parchment paper and fill with pie weights (or dried beans, which is what I prefer to use). Bake until the edge begins to turn light brown and the middle is half-baked. Remove from the oven and allow to cool to room temperature. Carefully remove the pie weights and paper.
2/3 c. blanched almonds
1/2 cube (4 oz.) unsalted butter
1/3 cup sugar
1 egg + 1 egg yolk
1 Tbsp brandy
Place the almonds in the bowl of a food processor and pulse until a fine powder forms. Add the butter and sugar and continue to pulse until you get a smooth paste. Add the egg, yolk, and brandy and pulse again until fully combined.
Pour the almond cream into the cooled tart shell. Cut six or seven medium-sized plums in half and remove the pits. Place each half cut side up into the cream, pressing them in gently so that they do not shift on the way into the oven. Top with sliced almonds and bake until the filling is golden, about 40-45 minutes.
Allow to cool a little, then top with more toasted almond slices and powdered sugar.