1 cup

Mix the dry ingredients and set aside. In a small bowl, blend the cream cheese and the granulated sugar until fluffy. Set aside. (Optional: add ½ cup chopped walnuts.)
   Make a well in the center of the dry ingredients. Add the wet ingredients all at once to the dry mixture, stirring until moistened. Batter should be lumpy. Fill muffin cup with 2 Tbsp batter. Spoon in 1 tsp of the cream cheese mixture, then fill each muffin cup three-quarters-full with batter.
   Bake at 350 degrees for 20 minutes. Dust with powdered sugar if desired.