Pumpkin Streusel Tart

For streusel: 3/4 cup pecans, toasted and chopped 1/4 cup firmly packed dark brown sugar 2 tablespoons all-purpose flour 1/2 teaspoon ground cinnamon 2 tablespoons unsalted butter, diced, cold For Pie: pastry for one 9″ pie 2 cups pumpkin puree, preferably fresh (cut Read on! →