INGREDIENTS
1 tsp
granulated sugar, for dusting muffin tin cups
4 tbsp
unsalted butter
1/2 cup
semi-sweet chocolate chips
1/4 cup
all-purpose flour
1/2 cup
confectioners' sugar
1/2 tsp
instant espresso powder
1
egg, plus 1 egg yolk
1/2 tsp
vanilla extract
1/4 cup
strawberry preserves (I used reduced-sugar)