In a large bowl, beat cream cheese and butter until smooth; add the eggs and mix well. Beat in the milk until smooth. Combine the flour, cornmeal, baking powder and salt; stir into cream cheese mixture just until moistened. Fold in the corn, salsa and onions. , Pour batter by 1/4 cupfuls into a large greased cast-iron skillet or hot griddle. Turn when bubbles form on top; cook until the second side is golden brown. Serve with sour cream and salsa.