Preheat oven to 350F,Grease a 9*13_inch cake pan.
Cream together butter and sugar until smooth.Add in eggs,one at a time,and beat until fully blended.
Add milk and vanilla,mix until combined.
In a seperat bowl, combine flours,salt and baking powder.Stir dry ingredients into wet ingredients. Beat until creamy.
Spread battet in prepared pan and bake for 30 minutes.Serve with fresh fruit or whipped cream.