Whip eggs in mixer bowl with sugar, espresso and vanilla on high speed for 15 minutes.
3
Meanwhile, melt bittersweet chocolate, unsweetened chocolate and butter in top of double boiler until almost melted. Remove from heat and continue stirring until smooth.
4
fold chocolate gently into egg mixture.
5
fold in dry ingredients
6
fold in mini chips
7
drop by teaspoon full onto parchment lined cookie sheets