Espresso Meringue Cookies

Adjust oven racks to upper and lower-middle positions. Preheat oven to 225º F. Line 2 cookie sheets with parchment paper.

In a small bowl, combine sugar, salt, cornstarch, and espresso powder. Set aside.

In a large bowl, using an electric mixer set on high speed, beat egg whites and vanilla until soft peaks begin to form. Reduce mixer speed to medium speed, gradually add the dry mixture in a steady stream down the side of the bowl. Set mixer aside and using a rubber spatula, scrape down the sides of the bowl once or twice. Increase mixer speed to high and beat mixture until stiff and glossy peaks form.

Quickly spoon meringue into a pastry bag fitted with a plain 1/2-inch tip. Pipe meringues into mounds 1-inch high and 2-inches wide, on prepared cookie sheets. Bake for 1 hour, rotating the pans halfway through the baking process. Turn off oven and let meringues cool in the oven for 1 to 2 hours.

Remove from oven and let cool to room temperature, about 8 to 10 minutes.

To Decorate:

Sprinkle cookies with grated toffee bits.

Melt butter in a saucepan over medium heat, stir in brown sugar and salt. Remove from heat source and allow to cool until tepid (about 25 minutes). Stir in confectioners' sugar and beat with an electric mixer until smooth and creamy.