Preheat the oven to 250 degrees F. Line a rimmed baking sheet with a silicone baking mat or parchment paper.
Put 1/4 cup blanched almonds and 1 teaspoon sugar into a food processor and pulse until it resembles cornmeal; reserve. Finely chop the remaining almonds.
In a stand mixer with the whisk attachment, beat egg whites and salt until very soft peaks have formed. In a small bowl, stir together the remaining 1/4 cup sugar and espresso powder. With the mixer running on low, slowly add in the sugar and the espresso powder, 1 tablespoon at a time, whipping just to the stiff peak stage, (do not overbeat). Gently fold in the reserved almond flour.
With a large offset spatula, spread the meringue batter on the lined baking sheet in an even layer, about 1/2-inch thick. Sprinkle the finely chopped almonds and chocolate chips evenly over the surface of the meringue and bake for 1 hour. Turn the oven off, leaving the meringue in the oven to dry out further and cool for an additional 1 hour.
Note: If meringue gets chewy, put it back into a 200 degree F oven for about 30 minutes, turn off the oven and let dry inside the oven while it cools.
To serve, break the meringue into pieces. Leftover meringues can be stored in an airtight container at room temperature in a dry cool place for up to 3 days.
Recipe courtesy of Claire Robinson