Melting chocolate with the butter in the microwave or in a water bath. Leave it to cool slightly and add it to the 2 eggs, stirring with a wire whisk. By stage add the flour and stir with wire. Then pour cola and stir vigorously until a thick liquid mixture. Add the dissolved in very little water instant coffee. Try and if it is very bitter, add powdered sugar to taste. The mixture is poured into paper trays muffins - about 2/3 of the forms are filled. I used small and large forms. In large set and one strawberry. muffins are baked in a preheated oven at 180 C for about half an hour. It is important to roast, because wither. Even match remains little of the mixture in check, do not worry - once cool, the muffins will be tight. The presence of chocolate inside, gives the illusion that may be undercooked. Ample 30 minutes. Once cool to room temperature, muffins decorate top with 1 strawberry or 1 small piece (small cakes). Spreads only strawberry jam with dissolved gelatin in a little water, not dry. After tightening of gelatin, optional can sprinkle muffins with icing sugar.