Place the butter, chocolate chips. And 3 tablespoons cocoa powder in a skillet over low heat. Cook, stirring, until the butter is fully melted and the mixture is smooth. Let cool slightly.
In a medium mixing bowl, whisk together ¾ cup Swerve Granulated, the flour, baking powder, and salt. Add the milk, egg, and vanilla, and whisk. Add to the skillet with the chocolate and whisk until fully combined.
In a small mixing bowl, combine the remaining ½ cup Swerve Granulated, remaining 4 tablespoons cocoa powder, and the Swerve Brown. Sprinkle over the cake batter in an even layer. Pour the hot coffee on and do not stir. Bake for 35 minutes or until the edges of the cake come away from the pan. Place the skillet on a wire rack and cool for 15 minutes before serving. Spoon some of the sauce from the bottom of the skillet over each piece of cake and dollop with whipped cream.