1. Preheat the oven to 425F. Fit the pastry into a 9-inch pie plate. Flute the edges, pressing the pastry to the side of the plate. Bake until lightly golden, about 12 minutes. Remove from the oven. Reduce the oven temperature to 350F.

2. To make the praline mixture, combine 2 tablespoons of the brown sugar and the flour in a small bowl. Cut in the butter with a pastry blender until coarse crumbs form. Stir in the pecans. Set aside.

3. Combine the remaining 1/2 cup brown sugar, the granulated sugar, cinnamon, ginger, allspice and salt in a large bowl. Stir in the pumpkin puree. Add the half-and-half and eggs and beat until smooth.

4. Pour the filling into the prepared piecrust. Sprinkle the praline mixture around the edge of the pie.  Bake until a knife inserted 1 inch from the edge comes out clean, 45 to 55 minutes. Cool on wire rack.

Tip
If the piecrust becomes too dark during baking, cover the edge with strips of foil.