Heat oven to 350°.
Grease the bottom of a 9x13 pan.
In a large bowl, blend all ingredients together at a low speed.
When combined, beat on high for 3 minutes.
Pour batter into the prepared pan.
Bake 40-45 minutes or until a toothpick inserted into the middle comes out clean.
Cool completely before frosting.
In a medium bowl, blend all ingredients together on high speed until smooth.
Spread over cooled cake.