1 1ouncebag mint-chocolate morsels, or dark chocolate/mint chocolate combo
Instructions
Bring kettle of water to boil. Adjust oven rack to second-to-lowest position and preheat to 350F.
Insert 2 long sheets of foil perpendicular to one another in baking pan, long enough to hang over edges. Push foil into corners and up sides of pan, smoothing foil against pan. Grease foil sling and set aside.
Whisk cocoa and boiling water (measure out correct amount from kettle of boiling water) together in large bowl until smooth. Add unsweetened chocolate and whisk until chocolate is melted. Whisk in oil and melted butter. Whisk in eggs, egg yolks, vanilla, and peppermint extracts. Continue to whisk until smooth. Whisk in sugar until fully incorporated. Sprinkle salt and sifted flour into batter and mix with rubber spatula until just combined. Fold in 1 cup of the mint/chocolate morsels.
Transfer batter into prepared pan, spreading into corners and smoothing the surface. Sprinkle with remaining chocolate/mint morsels. Bake about 30-33 minutes, rotating halfway through baking. It's done when toothpick comes out with moist crumbs attached; should not come out completely clean. It may seem underdone, but it will set upon cooling. Do not over bake, or brownies will be dry.
Transfer pan to wire rack and cool for 1 1/2 hours. Remove brownies from pan using foil sling. Return brownies to wire rack and let cool completely. Cut brownies into squares and serve. Can be stored in airtight container at room temp for a couple of days.