Here's one from "Mrs. Fields' I Love Chocolate! Cookbook."

Debbi's Deadly Chocolate Muffins

12 oz. semisweet chocolate, coarsely chopped
1 stick (1/2 cup) unsalted butter
1/2 c. sour cream
1 c. sifted cake flour
1/2 t. baking soda
1/4 t. salt
4 lg. eggs
1/2 c. (packed) light brown sugar
1 t. vanilla extract
1 1/4 c. semisweet chocolate chips
1/4 c. coarsely chopped macadamia nuts
1/4 c. white chocolate chips

Preheat oven to 350. Lightly oil the top surface of a 12 c. muffin tin. Line the cups with paper liners.
In a double boiler, melt the chopped semisweet chocolate with the butter & stir until smooth. Remove from the heat & stir in the sour cream.
In a small bowl, whisk together the flour, baking soda, & salt.
In a large bowl with an electric mixer, beat the eggs & sugar until light & pale, about 5 ming. Beat in the chocolate mixture & the vanilla. Add the flour mixture & 1 cup of the semisweet chocolate chips.
Spoon the batter evenly into the prepared muffin cups. Top with the remaining 1/4 c. semisweet chips, the macadamia nuts, & the white chocolate chips. Bake for 20-25 min., or until the centers are set.
Set the muffin tin on a wire rack to cool for 15 min. Then remove the muffins to cool completely.
Makes 12 muffins.

Hope this is what you wanted. I haven't tried them, but the picture in the cookbook looks luscious!