The Crust:
3 cups unbleached flour
1 tsp baking powder
1/2 tsp salt
10 Tbs unsalted butter, softened
6 Tbs vegetable shortening
3/4 cup sugar
2 large eggs
1/2 tsp vanilla extract

For the crust, combine the flour, baking powder, and salt in a medium-sized bowl and mix well.  Beat the butter and shortening together with an electric mixer on medium speed until smooth.  Gradually add the sugar and beat until the mixture is light and fluffy.  Beat in the eggs and vanilla, then reduce speed and add the flour mixture, mixing until just combined.  Gather the dough into a ball and flatten slightly, then, using your fingers, press into a buttered baking sheet about 13" x 18" x 3/4".  Refrigerate overnight or place in the freezer until firm, about 30 minutes.  Preheat oven to 375°F.  Prick crust all over with a fork and bake until golden, about 12 minutes. Cool.

The Topping:
1/2 pound unsalted butter
1/2 cup honey
1/4 cup sugar
1 1/4 cups brown sugar
1/4 cup heavy cream
4 cups chopped pecans

For the topping, combine the butter, honey, and sugars in a saucepan.  Simmer, stirring constantly, over medium heat until sugars melt and mixture darkens and foams, about 5 minutes. Remove from heat, whisk in cream and stir in pecans.  Spread evenly over crust with a spatula and bake until topping is bubbly, about 15 minutes. Remove pan from oven and cool completely on wire rack, then cut into 1 1/2 " squares or diamonds to serve.  Makes about 84 bars.