Set a rack in the center of the oven and preheat to 350 degrees F. You will need an ungreased 9x13-inch baking pan.
Crust: Cream the butter, sugar and maple syrup until smooth. Toss together the flour, Clabber Girl Baking Powder and salt, add to the creamed mixture just until blended. Press this evenly into the 9x13-inch pan and set in the freezer for about 15 minutes before baking.
Prick holes in the bottom of the pressed crust to allow steam to escape and bake for 25 minutes. Set aside to cool for just a few minutes. While the bar base is baking, prepare the topping.
Topping: Whisk together the brown sugar, Clabber Girl Corn Starch and Clabber Girl Baking Powder. Add the maple syrup and eggs, whisking until smooth. Stir in the pecans. Pour over the baked crust and return to the oven. Bake for 25 minutes or until the center is set.
Set on a rack to cool. Cut into bars and store in an airtight container for up to one week - separate the layers with parchment or wax paper to prevent sticking.
Yield: 15-18 bars.