Spray a 9x13 baking dish with nonstick spray. Set aside.
In a large bowl whisk together the butter and sugar. Add in the vanilla, eggs and salt and whisk until smooth. Using a rubber spatula stir in the flour until just combined. Finally stir in the sprinkles.
Spread the batter into the prepared pan.
Bake for 25-30 minutes until the edges are set. The bars might seen underdone, but allow them to cool completely.
FROSTING:
In a large bowl beat the butter for 1-2 minutes until it's smooth.
Turn the mixer to low and slowly add in the powdered sugar.
Next add in 2 tablespoons of coffee (or milk) and mix on medium speed until it's creamy, scraping the sides as necessary.
If the frosting is too stiff add in 1 more tablespoon of milk until the desired consistency is reached.
Finally add in 1-2 drops of pink food coloring and mix until a pale pink color is reached and evenly mixed.
Spread the frosting on top of the bars and garnish with more sprinkles, if desired.