Preheat oven to 375 degree F. Prepare and roll out Pastry for Single-Crust Pie. Line a 9-inch pie plate with the pastry. Trim and crimp edge high.
In a medium mixing bowl beat mascarpone or cream cheese, egg yolk, honey, and vanilla with an electric mixer on low to medium speed until smooth. Set aside.
In another medium mixing bowl stir together pumpkin, evaporated milk, the remaining 2 eggs, brown sugar, cinnamon, and nutmeg. Pour into pastry-lined pie plate. Dollop the mascarpone mixture over the pumpkin mixture. Pull a thin metal spatula gently through dollops to swirl fillings.
Bake for 50 minutes or until puffed and a knife inserted near the center comes out clean. Cool for 1 hour on a wire rack. Cover and chill at least 2 hours before serving.