Chocolate Surprise Cookies

1 cup butter, softened
1 cup brown sugar, packed
1 cup sugar
2 eggs
2 tsp. vanilla
3 cups flour
2/3 cup baking cocoa
1/2 tsp. baking soda
2 cups semi-sweet choc. chips
frozen mini. marshmallows
In mixer, cream butter and sugars until light and fluffy. Add eggs, beat in vanilla.  Gradually add flour, cocoa, and baking soda, mix well. Stir in choc. chips.
Scoop dough, with cookie scoop onto Silpat 2" apart. Press 3 frozen marshmallows into each. Bake @ 400 for 10 minutes, or until set, do not overbake. Cool 5 minutes and transfer to wire rack.
Note: I always find these cookies bake better after the dough has been in the fridge overnight, then allowed to soften slightly before scooping onto a baking mat. Then quicker they go into the oven after putting the frozen marshmallows on them the better.