Blueberry-Buttermilk Tart

Preparation

1. For the Crust

   1. Step 1

      To make crust: In a mixer, cream butter and sugar together until smooth and fluffy. Mix in yolks, vanilla and salt. Add flour all at once and mix just to combine. Add cream or milk and mix just until smooth. Form into a ball, flatten into a disk, wrap in plastic wrap, and refrigerate, at least 1 hour or overnight.

   2. Step 2

      On a floured surface, roll dough into a circle to fit a 10-inch tart pan. Transfer to pan and lightly press in, making sure dough rises about ¼ inch above rim. Refrigerate in pan 1 hour.

   3. Step 3

      Preheat oven to 350 degrees. Bake until barely golden, about 30 minutes. Check halfway through baking and prick any bubbles with a sharp knife. Let cool to room temperature.

   4. Step 4

      To make filling: whisk together sugar and cornstarch to remove any lumps. Whisk in egg, yolks, melted butter, buttermilk, vanilla or vanilla scrapings, salt and nutmeg, and pour into tart shell. Sprinkle surface evenly with 1½ cups blueberries.

   5. Step 5

      Heat oven to 350 degrees. Bake tart until surface is barely golden and still wobbly in the center, 35 to 45 minutes. Remove and let cool to room temperature. Serve at room temperature or lightly chilled, with a dollop of whipped cream (if using) and remaining blueberries scattered over each serving.