Preheat a convection oven to 350°F (175°C) and coat a 9x13 inch baking dish with non-stick spray.

In a medium mixing bowl, whisk the corn syrup, sugar, eggs, 1/2 cup melted butter, and vanilla extract until the emulsion is smooth.

Fold in the chopped pecans and distribute the mixture evenly into the bottom of the prepared baking dish.

Sift the dry yellow cake mix over the pecan mixture to ensure an even, clump-free layer.

Place the chilled butter pats in a grid pattern across the entire surface of the cake mix, ensuring maximum coverage for hydration.

Bake for 45 minutes or until the internal temperature reaches 200°F and the surface is a deep golden brown.

Remove from heat and allow the cake to cool for 30 minutes to permit the custard layer to set fully before portioning.