In the top of a double boiler over simmering water, MELT dark chocolate, butter and semisweet chips; STIR to blend.
In a large mixing bowl, BEAT eggs, sugar and vanilla; STIR in flour and chocolate mixture.
ADD pecans and marshmallows; POUR mixture into a heavily buttered 8x8x2-in baking pan.
BAKE in a preheated 350° F oven for 20 to 25 minutes; let COOL; CUT into squares.
Per Serving (excluding unknown items): 80 Calories; 5g Fat (51.9% calories from fat); 1g Protein; 9g Carbohydrate; trace Dietary Fiber; 21mg Cholesterol; 34mg Sodium. Exchanges: 0 Grain(Starch); 0 Lean Meat; 1 Fat; 1/2 Other Carbohydrates.