3tbspinstant coffee granules or instant espresso powder
2 1/4cups(450 g) granulated sugar
1 1/4cups(175 g) gluten free flour blend with xanthan gum (plus an additional 1/4 cup [35 g] for sprinkling on chocolate chips)
PEANUT BUTTER SWIRL:
1/2cup(113 g) butter, melted
1 1/2cups(375 g) peanut butter
1cup(125 g) powdered sugar
1/2cup(113 g) butter, softened
2cups(250 g) powdered sugar
1-2tspmilk, until desired consistency is reached
green food coloring, if desired
FOR THE BROWNIES:
Preheat oven to 350 degrees. Grease and flour half sheet pan (12 by 18 inch) and set aside.
In large bowl, add pound of butter, pound of chocolate chips, and 6 ounces of unsweetened chocolate. Melt either over double boiler or in the microwave on half power. Stir to combine and set aside to cool.
Mix 14 ounces chocolate chips with 35 g gluten free flour blend in small bowl and set aside.
In large bowl, whisk eggs with sugar, coffee, and vanilla until combined. Add melted chocolate mixture and whisk to combine.
Sift the rest of the flour, baking powder, and salt and add to chocolate mixture. Stir to combine.
Add chocolate chip and flour mixture to the rest of the batter and stir to combine.
Pour batter into prepared pan and smooth top. Add peanut butter mixture to half the brownies and swirl to combine. It doesn't have to be perfect.
Position large piece of foil underneath oven rack to catch any drips from peanut butter mixture. Bake for 20 minutes. Open oven door and tap pan on oven rack to release brownies from pan. Continue to bake brownies for an additional 15 minutes, or until toothpick inserted in center comes out clean. Do not overbake.
FOR THE PEANUT BUTTER SWIRL:
Mix melted butter, peanut butter, powdered sugar, vanilla, and salt in small bowl until well combined.
FOR THE BUTTERCREAM:
In small bowl, mix butter, powdered sugar, vanilla, and milk until well combined. Add green food coloring if desired.
Fill pastry bag and using star tip, pipe zigzag to brownies as desired. Alternatively, spread buttercream on brownies as desired.