1 (18 ounce) package yellow cake mix
6 tablespoons butter
1 cup all-purpose flour
1 teaspoon baking powder
1 1/2 tablespoons white sugar
1 1/2 cups milk
1 teaspoon vanilla extract
1 cup vegetable oil
1 cup white sugar
1/2 cup butter, melted
1 cup vegetable oil
1 1/2 cups white sugar
1 1/2 cups corn syrup
Preheat oven to 375 degrees F (190 degrees C). Grease and flour a 10x15 inch pan.
In a large bowl, mix together cake mix, butter, flour, baking powder, and sugar. Mix in milk, vanilla extract and oil; beat until smooth. Stir in the sugar mixture by hand until the dough is incorporated. Cover and refrigerate overnight.
On a floured surface, roll the dough out to 1/2 inch thickness. Cut into 1 inch squares. Place squares into prepared pan.
Bake for 15 to 20 minutes in the preheated oven, or until a toothpick inserted into the center comes out clean. Cool completely.
In a large bowl, cream together the white sugar and butter until smooth. Beat in the flour mixture, then beat in the milk, eggs, vanilla extract and vegetable oil; beat until light and fluffy. Beat in the corn syrup.
Remove from refrigerator, and brush with the remaining flour mixture. Return to the refrigerator, covered, for at least 10 to 12 hours.
Remove from refrigerator, and cool completely. (Note: This may be re-covered in the refrigerator.)