As seen on Facebook:
adapted from Smells like Home
1 cup unsalted butter, at room temperature
1 1/2 cups granulated sugar
1 1/2 cups brown sugar
4 large eggs, at room temperature
2 oz red food coloring (optional)
4 tsp pure vanilla extract
2 1/2 cups all-purpose flour
6 tbsp unsweetened cocoa powder
1/2 tsp salt
Preheat the oven to 350 degrees F. Butter and flour an 9 X 13 clear glass baking pan.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the butter and sugar on medium speed until light and fluffy, about 2 minutes. Add eggs one at a time, mixing well after each addition, then stir in food coloring (if not using food coloring add 4 T of water or milk) and vanilla, mix until the color is fully incorporated. Mix flour, cocoa and salt in a separate bowl. Slowly add in the flour mixture being very careful not to over mix.. Do not over mix. The batter will be very thick.
Remove the bowl from the mixer and stir up the batter with a rubber spatula once or twice just to ensure all of the flour has incorporated from the sides of the bowl and there isn’t anything stuck on the bottom of the bowl. You’ll want one uniformly colored (red) batter.
Pour the batter into the prepared pan and bake for 30-40 minutes. 35 minutes for a thin crust on top and gooey underneath. Set aside to cool, cut into bars and serve.