In small bowl, combine flour, pumpkin spice, baking powder and baking soda.
In large bowl, beat butter, sugar and brown sugar until crumbly. Add eggs, egg whites, pumpkin and carrots. Beat until well blended. Add flour mixture and mix until well blended. Spread onto greased pan.
For Cream Cheese Topping, mix together cream cheese, sugar and milk until thoroughly blended. Drop by teaspoons over pumpkin batter and swirl mixture with a butter knife. Bake for 20-25 minutes or until cake tester comes out clean.
Cool in pan completely on wire rack before cutting into squares.