Preheat the oven to 400F. Rub the inside of a 3-cup soufflé mold (either one big one or several mini ones) with 1/4 Tbsp butter. Coat the bottom and sides with sugar. Knock out excess sugar. If using mini molds, place them onto a cookie sheet for easy carrying.
In a medium saucepan, whisk together the flour, milk, and sugar. Heat it for a few minutes. Right before it boils, whisk in the espresso powder, cinnamon, and clove. Bring it to a boil until mixture thickens. Remove from the heat and beat for 2 minutes to cool slightly. Beat in the egg yolks, one at a time, until smooth. Beat in the butter and set aside.
In a large mixing bowl, beat the egg whites and salt until soft peaks form. Sprinkle on the sugar then continue beating until stiff peaks form.
Beat the vanilla into the espresso base. Stir in fourth of the egg whites. Delicately fold in the rest.
Fill the soufflé mold(s), leaving a little bit of space before the rim. If the mold is too full, it will spill over as it rises. Put the mold(s) into the oven and immediately turn the temperature down to 375F. Bake around 15 minutes for mini molds and around 30 minutes for large mold. They are done when a toothpick or knife inserted in the middle comes out clean. Pull out of the oven then sprinkle with powdered sugar. Serve immediately.
Recipe by Chocolate Moosey at http://www.chocolatemoosey.com/2012/08/05/espresso-souffle/