1.
Preheat oven to 350 degrees.
2.
Spray the bottom and sides of a 8x8 inch square baking pan and set it aside.
3.
Add 2/3 cup butter and chocolate to a small saucepan. Melt over low heat, stirring constantly, until smooth. Remove from burner and allow to cool for 10 minutes.
4.
In the bowl of a stand mixer, combine the granulated sugar, 1 tablespoon vanilla, and eggs. Beat on high speed for five minutes. Reduce the speed to low and slowly pour in the cooled chocolate mixture. Add the flour with the mixer running on its lowest setting and beat until just combined.
5.
Pour the mixture into the prepared pan and smooth with a rubber spatula so that it's spread out evenly.
6.
Bake for 45 - 50 minutes, or until a toothpick inserted into the center comes out clean.
7.
While the brownies are baking, make your frosting. In the bowl of a stand mixer, beat the 5 tablespoons of butter on high speed until it's fluffy in texture (about 2 minutes). Reduce the speed to low and add the confectioners sugar a little at a time until it is all added. The mixture should have a crumbly texture. Slowly add the milk and 1 teaspoon of vanilla to the mix. Then, turn the mixer to high and beat for 2 more minutes
8.
Reduce the mixer speed to low and add the sugar a little at a time until it is all added. The mixture should have a crumbly texture.
9.
Color the frosting pink by adding a few drops of red food coloring (optional). Remember that with food coloring, very little goes a long way.
10.
Once your brownies are bakes, allow them to cool completely. Then, cut them into 1x1-inch squares and frost. Add a candy heart to the top of each brownie, if desired.