3/4 cup plus (optional) 2 tablespoons granulated sugar
6 tablespoons unsalted butter
1/4 teaspoon flaky sea salt or just 2 or 3 pinches of a coarse one
10 to 12-ounce loaf brioche or challah bread (cut into slices about 1/2-inch thick and about 3 inches square or round, which sounds really persnickety, but they really do fit better in the pan this way)
8 large eggs
1 cup mascarpone cheese, divided (1/4 cup for custard; 3/4 cup for serving)
1 cup milk
1/4 teaspoon almond extract