Nothing says “Summer!” quite like fresh berries. Put them in top of a tart with a mascarpone cream filling and the result is a dessert that will leave everybody longing for more. It’s also a treat that goes exceptionally well with a well chilled bottle of dessert wine such as Dulce Vengaza Late Harvest Chardonnay, Kiona Fortunate Sun Late Harvest Chenin Blanc, or Kiona Chenin Blanc Ice Wine.
Combine 1 ½ cup all-purpose flour, ½ cup powdered sugar, and 1/8 tsp salt in a food processor. Pulse to mix. Add 10 Tb of cold unsalted butter cut into ½ inch cubes and pulse several more times until the largest piece of butter is the size of a pea. Lightly beat an egg with a fork and add and ¼ tsp of vanilla extract to food processor. Pulse a few more times until the dough begins to form clumps and pull away from the side.
Lightly grease a 10 inch removeable bottom tart pan with butter. Press dough into pan spreading it evenly across the bottom and up the sides. Place tart pan with dough in freezer for 1 hour.
Preheat oven to 375°F. Line the frozen tart crust with aluminum foil, and fill with pie weights. Place tart on middle rack in oven. Bake for 20 minutes. Remove pie weights and foil. Pierce the crust bottom in several places with a fork and then bake crust for another 10-15 minutes until golden brown. Remove from oven and cool completely before filling.
Combine 8 oz mascarpone cheese, ¼ cup cold heavy cream, 1/3 cup powdered sugar, 1 tsp orange zest, and ½ tsp vanilla extract in a chilled bowl. Beat using an electric mixer on high speed until stiff peaks form. Transfer mascarpone mixture to tart and spread evenly so that it is level. Top with raspberries, blueberries, blackberries, and halved or quartered strawberries (stem removed).
Combine 4 Tb apricot jelly or orange marmalade, 2 Tb water, and 1 tsp red wine vinegar in a small saucepan. Heat over medium heat until jam or jelly has dissolved, and mixture is bubbly. Spread glaze over berries using a pastry brush.
Remove the rim of the tart pan before serving.