Prepare the crust: In a large bowl, combine the cake mix, melted butter, and
1 egg. With an electric mixer on low speed, beat for 2 minutes, or until blended.
The batter should come together in a thick dough.
With your fingertips, pat the dough evenly over the bottom and 1 inch up the
sides of a 9 x 13-inch baking pan to form a crust, smoothing the surface.
Bake the crust for 20 minutes, or until it just begins to brown.
Remove the pan from
the oven and set it aside while you prepare the filling. Leave the oven on.
In the same large bowl used for the crust with the same beaters (no need to clean
either), combine the corn syrup, brown sugar, 2 eggs and vanilla extract. With mixer
on medium speed, beat ingredients 1 minute, or until well combined.
With a rubber
spatula, scrape the sides of the bowl and fold in the pecans until well distributed.
Pour the filling over the baked crust and spread it with the rubber spatula to
cover the entire surface.
Bake the cake for 22-25 minutes, or until the crust is golden and the filling just
starts to set.
Place the pan on a wire rack to cool for 30 minutes.