Preheat oven to 350. Line a 9 x 13 baking dish with parchment paper or foil and spray with cooking spray.
Melt the unsweetened chocolate and butter in a glass bowl in the microwave. Add the rest of the brownie ingredients and stir until smooth.
Pour into the prepared baking pan and spread evenly. Bake for 20-25 min or until no longer jiggly. Cool completely.
Heat the cream in the microwave for 2 minutes or in a saucepan over medium heat until bubbles form around the edge. Remove from heat and add the chocolate. Stir until melted. Add the sweetener and whisk until smooth and shiny. Pour over the cooled brownies and spread evenly.