Preheat oven according to brownie package instructions.

Mix brownies according to package instructions.

Pour brownie batter into a greased 13×9-inch pan and place in the oven to bake for 23 minutes. (The cooking time for all brownie mixes is different. This brownie mix cooking time was 33 minutes, but I cooked it 10 minutes less. I suggest subtracting 10 minutes from the cooking time on the box or cooking it for 2/3 of the time.)

While the brownies cook, whisk together the sugar, corn syrup, eggs, butter, and vanilla in a small saucepan. Place the saucepan on the stovetop over medium-high heat and begin to cook, stirring continuously. Cook the filling until it begins to thicken. Add the pecans into the mixture and continue to cook until the mixture is thicker but pourable. You still want it to be pourable.

When the brownies have finished with the first round of baking, remove them from the oven, poke the top with a fork or skewer, and pour the pecan pie filling over them, spreading it out to cover the brownies completely.

Place them back in the oven and bake for 15-20 minutes or until the filling seems pretty set. Let cool to room temperature before cutting