To call this a glaze doesn’t really do it justice. When we hear glaze, we think of the clear, sweet topping poured on donuts and other breakfast desserts.
This glaze, on the other hand, is thick and chocolaty, almost like straight melted chocolate-with a little more “binding” ability that makes it perfect for cookie sandwiches.
In fact, C calls it an “easy ganache,” which isn’t a bad way to think of it.
Unsweetened chocolate, coarsely chopped
Semisweet chocolate, coarsely chopped
Strained confectioners’ sugar, spooned in and leveled
Boiling water, plus additional as needed
Light corn syrup
Pure vanilla extract
Melt the chocolates and butter in a shallow bowl set over simmering water, stirring until smooth. Remove from the heat and add the sugar alternately with the water. Stir in the corn syrup and vanilla. Beat well with a wooden spoon.