Makes two 8 1/2 -inch tarts
YOU WILL NEED
Two 8 1/2 -inch tart shells, blind baked
3 peaches or nectarines, or 2-3 cups fresh rasperries or blueberries PER TART (you'll need six peaches for two tarts).
12 oz sugar (1 1/2 cups plus 1 T)
2 oz sifted flour (scant half cup)
8 oz (2 sticks) unsalted brown butter (see METHOD below)
½ vanilla bean, seeds scraped
Whisk sugar and eggs together in a medium bowl. Add flour and whisk until smooth.
Make brown butter:
In a stainless steel saucepan (or one with a light-colored bottom), add 2 sticks unsalted butter and scraped vanilla bean. Melt the butter over low-medium heat. Once melted, turn up heat to medium and continue to cook until it turns a deep nutty brown, about 8 minutes. Carefully remove vanilla bean and slowly whisk browned butter into sugar-egg mixture. Use some caution here - the mixture will bubble up substantially when you add the hot butter. Strain the mixture and reserve.
Arrange berries, peach or nectarine slices in bottom of cooled crust. If using berries, just scatter a handful (you will top the baked tart with fresh berries after it has baked and cooled). If using peaches or nectartines, slice about 3 large pieces of fruit per tart and arrange slices neatly on the baked crust.
Pour half the brown butter mixture evenly over the fruit. Place tart on rimmed baking sheet and bake until filling is puffed and golden, about 45 minutes. Cool tart for 15-20 minutes, then remove tart pan sides. Once cooled, you can dust it with a shake or two of powdered sugar. Serve at room temperature or warmed.
Can be made 1 day ahead. Store covered at room temperature.