Combine baking mix and sugar in a large bowl; stir in chocolate and nuts. Make a well in center of mixture. Combine half-and-half and remaining 3 ingredients; add to dry ingredients, stirring just until dry ingredients are moistened.
Spoon into greased muffin pans, filling two-thirds full. Bake at 400° for 11 to 12 minutes or until a wooden pick inserted into center comes out clean. Remove from pans immediately.
Hot Chocolate Muffins: Omit whtie chocolate and macadamia nuts. Decrease baking mix to 2 1/4 cups and half-and-half to 1/2 cup. Stir in 2 tablespoons cocoa, 3/4 cup semisweet chocolate mini-morsels, 1/4 cup chocolate syrup, and 1/4 cup sliced almonds. Bake as directed. Yield: 1 dozen
Ham and Cheese Muffins: Omit sugar, chocolate, nuts and vanilla. Add 3/4 cup diced ham (for maximum flavor, use country ham) and 3/4 cup shredded sharp cheddar cheese. Bake as directed. Yield: 1 dozen