Low-Fat S'Mores Fudge

8 ounces reduced-fat semisweet chocolate-flavor baking chips
2/3 cup non-fat sweetened condensed milk (not evaporated milk)
1 teaspoon vanilla extract
1 1/3 cups miniature marshmallows
2 low-fat graham crackers, broken into small pieces.

Line an 8-inch square pan with aluminum foil, then grease the foil.

Cook the chips and condensed milk in a heavy saucepan over low heat, stirring often until melted and smooth. Remove from heat, let cool 2 minutes, and then stir in the vanilla extract and 1 cup of the marshmallows.