Cream cheese filling:
Heat oven to 425°F. Dust a non-stick 12x8 pan with a little Carbquik.
Cut the cream cheese and butter into the Carbquik. Mix in the Splenda. Stir in the cream. Knead the dough 8 to 10 times with your hands.
Put the dough in the non-stick pan and press the dough flat so that it fills the pan (some folks prefer to use parchment paper and roll the dough). Spread cream cheese filling (see directions below) down the center of rectangle. Fold the sides up to cover the filling. Mix Splenda and cinnamon and sprinkle it over the top.
Bake 12 to 15 minutes or until golden; cool 10 minutes. Carefully place on wire rack; cool completely. Refrigerate any remaining coffee cake.
CREAM CHEESE FILLING:
Mix all ingredients together until smooth.