First, preheat oven to 350F.
Next, In a large mixing bowl, beat eggs and vanilla extract. Add sugar and melted butter and mix until blended.
Then, add flour, cocoa powder, baking powder, and salt. Mix just until blended.
Then, pour into a greased 13"x 9"x 3" baking dish and bake at 350F for 35 minutes or until a toothpick inserted comes out clean.
Next, divide the icing batch into thirds. Add one drop of yellow food coloring to one third of the icing to make yellow icing. Add one drop of red food coloring to one third of icing to make pink icing. Add one drop each of red and blue food coloring to make lavender icing.
Next, spread frosting over the top in a thin layer onto each brownie.
Then, with a wet knife, gently smooth out the icing to make it flatter.
Next, using red gel icing, very thinly write short phrases on top of the buttercream frosting
Do not let it melt for too long in your microwave or it will start splattering all over the inside of the microwave. Be careful removing the hot bowl containing the melted butter from the microwave. Use a pot holder or kitchen towel.
Because these brownies are spread with butter cream frosting, they should be stored in the refrigerator for up to 3 days.