Brownies with Chocolate and Peanut Butter Frosting

My sister came over for dinner on Sunday night and while I was still trying to figure out what to make for dessert, we both talked about having cravings for Friendly's Reeses peanut butter cup sundaes. You know those delicious little prepackaged sundaes where the chocolate and peanut butter topping looks a little bit, or a lot, like plastic? Mmmm. So I did a search on Epicurious of "peanut butter" and "chocolate" and came up with this recipe for Peanut Butter and Fudge Brownies with Salted Peanuts. They were good, but by the time we had finished eating dinner, we were too stuffed to eat all 30 brownies. Darn. So if you haven't had any yet, and you'd like some, I still have about 20 or so left.

I don't have a lot of patience for cutting baked goods into squares, so they came out a lot more rugged looking than the photo on Epicurious, but unless you're really trying to impress someone, does it matter?

Lastly, I don't mess around with ingredients or instructions in baking recipes, so this one is pretty much straight from Epicurious. I think the salted peanuts in the brownies could be made optional, they were fairly peanut buttery as is.

Ingredients

Brownies
3/4 cup (1 1/2 sticks) unsalted butter
7 ounces bittersweet or semisweet chocolate, chopped
3 ounces unsweetened chocolate, chopped
1 1/2 cups sugar
1 1/2 teaspoons vanilla extract
1/4 teaspoon salt
4 large eggs
1 cup all purpose flour
1 cup roasted salted peanuts, chopped

Frosting and ganache

1 cup chunky peanut butter (the bad for you kind, not the natural kind)
1/2 cup (1 stick) unsalted butter, divided, room temperature
3/4 cup powdered sugar
1/8 teaspoon salt
1/8 teaspoon ground nutmeg
1 tablespoon whole milk
1 teaspoon vanilla extract
7 ounces bittersweet or semisweet chocolate, chopped
For brownies:
Preheat oven to 325 and place oven rack in the center. Line 13x9 baking pan with foil, leaving a long overhang on each side; butter foil.
Place 3/4 cup butter in heavy large saucepan. Add both chocolates. Stir over low heat until smooth. Remove from heat. Whisk in sugar, vanilla, and salt, then eggs, 1 at a time. Fold in flour, then nuts. Place mixture in pan. Bake until a toothpick inserted into center comes out with moist crumbs attached, about 30 minutes. Cool brownies for a while.
For frosting and ganache
Using electric mixer or food processor, beat peanut butter and 1/4 cup butter until blended. Beat in powdered sugar, salt, and nutmeg, then milk and vanilla. After the brownies have cooled, spread the peanut butter mixture over them.
Stir chocolate and 1/4 cup butter in heavy small saucepan over low heat until smooth. Drop ganache all over frosting; spread to cover. Chill for about 1 1/2 hours.
Using foil, pull brownies out of the pan and cut into squares.