1. Melt the butter, mascarpone, and chocolate together over a double boiler.
2. Sift flour and cocoa together.
3. In a mixer with a whisk attachment whip eggs, sugar and extract for 8 minutes on medium speed until light and fluffy.
4. Turn the mixer down to low.
5. Add butter and chocolate mixture while the mixer is turning slowly.
6. Then, add the flour mixture. Mix until combined for 30 seconds to 1 minute, no longer or you can get a cake brownie by forming gluten. Be sure all the ingredients are incorporated evenly.
7. Pour onto a half sheet pan that is lined with parchment and heavily sprayed with pan spray.
8. Bake at 325º convection starting at about 15 minutes.
9. A crust will form and will pull away from the sides. It will not pass the butter knife or tooth pick test.
10. Let cool completely at room temp. Chill chocolate brownies in the fridge for 1-2 hours. Then cut to desired size.

For the lime glaze:

1. Zest 2 limes, and juice them.
2. Place on mixer with paddle attachment and add powdered sugar and mix until desired consistency is reached! Drizzle over chocolate brownies.