Preheat oven to 350F.
Prepare a 15'x10'x1' jelly roll pan.
Mix cake mix with eggs, Irish Cream and oil.
Set aside 1/2 cup of prepared cake batter for swirl.
Pour cake batter into prepared pan.
In a small bowl, blend all swirl ingredients.
Drop large spoonfuls of this mixture over the cake batter.
Swirl with a fork to make a marble effect.
Bake 25-30 minutes. Cool and cut into squares.