Add butter and sugar to a mixing bowl and beat together until light and fluffy, about 3 minutes. Add the eggs and vanilla and mix well.
Stir together the flour, baking powder, and salt and add to the mixing bowl. Mix just until dough is combined.
Flour your hands and press the dough evenly into 9x13'' baking sheet lined with parchment paper. Bake for 12-15 minutes or until the crust is set but not browned.
Add butter, corn syrup, and brown sugar to a saucepan over medium heat and stir until butter is melted.
Bring to a slow boil and boil for 3 minutes.
Remove from heat and stir in heavy cream and chopped pecans. Pour over the crust and smooth into an even layer.
Bake for 25 to 30 minutes or until the filling is set. The pecan bars are done when the edges are set and the center only slightly jiggles when the pan is moved.
Allow to cool completely, then cover and refrigerate for at least 2 hours before cutting and serving.
Make Ahead Instructions: Once baked and cooled, cover and store in the refrigerator for up to 5 days.Freezing Instructions: Allow to cool completely, cover well and freeze for up to 3 months. Thaw overnight in the refrigerator then bring to room temperature before serving.Recipe adapted from Ina Garten