Preheat oven to 350F (175C) and line a 9×13 metal baking pan with parchment paper or foil, using enough so that the excess hangs over the sides (you’re effectively making a sling that you’ll use to remove the bars after baking and cooling).

Combine flour, sugar, cornstarch, and salt in the basin of a food processor and briefly pulse until combined.

Scatter butter over the top of the mixture and pulse again until just combined and small butter pieces are still remaining.

Add heavy cream and pulse again until dough is still sandy/just beginning to cling together but will stick together if pressed between your thumb and forefinger (this is about 25-30 one-second pulses for me).

Pour crumbly mixture into prepared baking pan and use your hands or the back of a spoon to evenly flatten into the pan.

Transfer to 350F (175C) oven and bake until the crust is just beginning to turn light golden brown, about 25 minutes. While crust is baking, prepare your pecan pie bar topping.

Melt butter and set aside so it has some time to cool.

In a large bowl, combine brown sugar and flour and whisk until well-combined and lump free.

Add eggs, corn syrup, vanilla extract and salt and stir until completely combined and then drizzle in melted butter and stir to combine.

Stir in chopped pecans.

Once crust has finished baking, pour pecan pie filling over warm crust (use a spatula to evenly distribute the filling/nuts if needed). Return to oven and bake on 350F (175C) for 25-30 minutes or until the filling is set and the center does not jiggle or very barely jiggles when the pan is jostled (note that over-baking can result in a mealy textured filling while under-baking can leave you with runny filling).

Allow to cool for 4-6 hours or overnight before removing from the pan and cutting and serving.