1 sheet frozen puff pastry, thawed
11 tablespoons unsalted butter
1 cup granulated sugar
3 1/2 tablespoons all-purpose flour
1 1/2 teaspoons vanilla extract
1 cup fresh raspberries
Confectioners` sugar, for dusting(optional)
Position a rack in the lower third of the oven; preheat the oven to 350 F.
Unfold the pastry on a lightly floured surface and roll it out to a rough 12-in square. Fit it into a 9-in fluted tart pan with a removable bottom. Trim the dough even with the top of the pan. Refrigerate while you proceed.
In a small heavy saucepan, melt the butter over high heat, then cook for 8 to 10 minutes, until it is golden brown and has a nutty aroma.
Meanwhile, in a medium bowl, whisk the eggs and granulated sugar until well blended. Whisk in the flour.
Gradually whisk the browned butter into the egg mixture. Whisk in the vanilla until combined.
Scatter the raspberries evenly over the bottom of the tart shell. Slowly pour the filling evenly over the berries.
Bake the tart for 45-50 minutes, until the top is golden brown and the filling is set. Let the tart cool completely on a wire rack. Serve at room temp, or refrigerate and serve chilled. Just before serving, dust the top with confectioners` sugar, if desired.