In a large bowl cream together your butter and
sugar. Add eggs and vanilla and mix well until
smooth. Add your dry ingredients and stir until
just combined. Do not overmix. Batter will be
very thick.
Pour the batter into prepared pan, smooth it out
as best as you can (It is thick) and bake for 20-25
minutes until a toothpick inserted into the center
comes out clean. Err on the side of underbaking
if you are questioning.
Remove from the oven and let the brownies sit for
about 15 minutes. You want them to still be warm
when you pour on the icing. Once you remove the
brownies from the oven, make your icing by
mixing all 4 ingredients together until smooth.
Pour the icing over top of the still very warm
brownies. Cool completely and serve.