Mix base ingredients well. Spread in a greased 9"x13" baking pan.
Next, prepare the top layer.
Put the softened cream cheese in a large bowl or the bowl of a mixer.
Add eggs and vanilla, mixing to well incorporate.
Add butter and mix well.
Put in powdered sugar, a bit at a time, mixing until the sugar is all incorporated.
Add the chocolate chips and toffee pieces.
Mix until incorporated, but do not over mix.
Pour this mixture over the base in the pan.
Bake for 35 - 40 minutes, until the top is golden.