Beat the softened butter and powdered sugar until smooth. Then mix in the whole egg and egg yolk. After that, add the flour and salt and mix on low just until no dry streaks remain. The dough should come together without looking overmixed.

Press the dough together, divide it in half, and flatten each half into a disc. Wrap each disc tightly and chill for at least 1 hour. Use one disc now and save the other for later. When you are ready, roll one disc into an 11-inch round on a floured surface, then fit it into a 9.5- or 10-inch tart pan with a removable bottom. Press it into the sides, trim the extra dough, and prick the base with a fork. Chill the shell for 15 minutes while the oven heats to 375°F.

Line the tart shell with parchment and pie weights. Bake it for 8 minutes, then remove the weights and bake for 6 minutes more. After that, let the shell cool while you lower the oven to 350°F.

Beat the pumpkin puree, both sugars, and maple syrup until smooth. Then beat in the eggs. Next, add the salt, cinnamon, pumpkin pie spice, milk, and cream, and mix on low until combined. Pour the filling into the cooled shell and bake for 35 to 40 minutes, until the center is set and no longer jiggles much in the middle.

Set the tart on a rack and let it cool to room temperature, which takes about 2 hours. Then refrigerate it for at least 4 hours, or overnight if you can.

Before serving, drizzle the tart with melted white chocolate and scatter the toasted pecans over the top. Then slice and serve.