Preheat oven to 400°. Whisk together cheese spread, butter, sour cream and egg until blended. Add muffin mix; stir just until moistened. Fold in bacon.
Fill 10 greased or paper-lined muffin cups three-fourths full. Bake until a toothpick inserted in center comes out clean, 10-12 minutes. Cool 5 minutes before removing from pan to a wire rack. Serve warm.