In a large bowl, on the medium speed of an electric mixer, beat together the cream cheese, butter and sugar until smooth, about 3 minutes. Add the eggs and beat well. Add the dry ingredients in two parts, alternating with the milk and vanilla.
Spoon the batter into the muffin cups, filling them about two-thirds full. Drop 3 small dollops (about a teaspoonful each) of raspberry preserves onto the top of each bun and, using the tip of a sharp knife, swirl the preserves into the batter, forming a decorative pattern.