Peanut Butter Fudge

Butter the bottom and sides of an 8- x 8-inch pan, then line with parchment paper. (The butter helps the paper stick to the pan.) Lightly butter the top of the parchment paper, as well. Combine the 1 cup butter and peanut butter in a large microwave safe bowl, cover with plastic wrap and microwave on full power for 2 minutes. Carefully remove from the microwave, stir, then microwave on full power for an additional 2 minutes. Remove the bowl from the microwave. Carefully stir in the vanilla and confectioners' sugar with a wooden spoon or rubber spatula until evenly combined. The mixture may become a little crumbly at first, but continue to stir until the ingredients are smooth and a nice "dough" forms. Pour the mixture into the prepared pan and spread into an even layer, pushing to fill the corners. Place an additional square piece of parchment paper directly on the surface of the fudge. Refrigerate at least 2 hours. Use a large knife to cut into 1-inch cubes. Store in an airtight container at room temperature for up to 1 week. Source: Barely adapted from Annie's Eats, originally from Alton Brown, via The Food Network