Wild Blueberry Tart

Name: Wild Blueberry Tart
Ingredients: 1 cup rolled oats; 1⁄4 cup finely chopped blanched almonds or walnuts; 14 Tbsp. unsalted butter, at room temperature; 1⁄2 cup plus 3 Tbsp. sugar, divided; 1 tsp. vanilla extract; Pinch ground cinnamon; Pinch fine salt; 1¼ cups all-purpose flour; 3½ cups blueberries, preferably wild; 2 Tbsp. cornstarch; 2 tsp. finely grated lemon zest; 1⁄4 cup red currant jelly or strawberry or raspberry jam (optional); Whipped cream and vanilla ice cream, for serving (optional)