• Preheat oven to 325 degrees F.
• Butter a 13 x 9-inch pan or two 9-inch round pans and set aside.

To make the Brownies:

• In a small saucepan, melt the butter and bring it to just below a boil. Place the chocolate chips in a large bowl. Pour the hot butter over the chips and let stand for 30 seconds. Stir until completely melted.
• Sift in the sugar and cocoa powder. Beat in the mascarpone, eggs, and vanilla.  Mix until smooth. Gently fold the flour and salt into the batter.
• Pour the batter into the prepared baking pan(s) and spread evenly. Bake for 30 - 45 minutes for the 13 x 9 pan, or 20-30 minutes for the 9-inch round pans. Meanwhile make the ganache.

To make the Ganache:

• Place the chocolate chips in a large mixing bowl and set aside.
• Place the blueberries and sugar in a small saucepan over medium heat. Cook and stir until the mixture becomes sauce-like and bubbly. Pour into a sieve or strainer that is placed over the bowl containing the chocolate chips to catch the blueberry liquid. Discard the remaining blueberries.
• Bring the cream and butter to just below boiling in a small saucepan over medium heat. Pour the hot mixture over the chocolate and let stand for 30 seconds. Stir the mixture until smooth. The ganache should be warm when used for spreading.

Assemble the Brownies:

• Once brownies are baked, cool for 10 - 15 minutes.
• Spread the warm ganache over the brownies. Allow the ganache to set completely before cutting into squares.