Shortcut Version...from The Kitchen Witch Blog
Preheat the oven to 350°.
1 stick butter, plus more for pan
8 oz semi-sweet chocolate
1 1/2 c sugar
4 large eggs
1 t vanilla
3/4 c flour
1/4 t salt
1 8-ounce bag Mini Oreos, to garnish
Preheat oven to 350º. Line 8" square baking pan with nonstick foil or foil sprayed with Pam. Set aside.
Place butter and chocolate in microwave safe bowl and microwave gently until butter and chocolate are melted (about 30 seconds x 3, stirring in between sessions). Let cool to room temperature.
Stir sugar into chocolate till combined. Whisk in eggs one at a time, then vanilla. Fold in flour and salt. Pour into prepared pan and smooth top with offset spatula. Bake until cake tester comes out of center with just a few moist crumbs, 40-45 min. Cool completely on rack.
In a standing mixer fitted with a whisk, mix together sugar and butter. Mix on low speed until well blended and then increase speed to medium and beat for another 3 minutes.
Add vanilla and 1 tablespoon of cream and continue to beat on medium speed for 1 minute more, adding more cream if needed for spreading consistency.
Spread frosting over cooled brownies with offset spatula. Garnish with as many mini Oreos as you'd like. To serve, use foil to pull brownies out of pan and cut into bars.