cream butter with cream cheese, sugar, and corn starch.
add egg, milk, vanilla
beat on high until smooth and creamy
set aside in small bowl
combine dry ingredients in bowl.
add butter and 1 cup milk and mix with electric mixer
add one third cup milk, eggs, chocolate and vanilla. beat 1 minute
grease and flour 13 x 9 pan.
spread half chocolate batter, Spread cream cheese batter over,
spread remaining chocolate batter
bake 50 to 60 minutes are 350
cool and ice with chocolate frosting