Preheat the oven to 350 degrees F. Place an oven rack in the middle position. Lightly grease a mini bundt pan (I prefer using baking spray with powder).
Whisk together the flour, baking powder and salt in a medium bowl. Sift in the cocoa powder and whisk until the dry ingredients are evenly combined. In a separate small bowl, combine the half and half, Chambord and vanilla extract.
In a stand mixer with the paddle attachment, cream the butter and sugar together on low speed for 5 minutes. Add the eggs, one at a time, allowing each egg to incorporate before adding the next. Scrape down the sides of the bowl. Add the melted chocolate. With the mixer still on low speed, swiftly alternate between adding the dry and liquid ingredients over the course of a minute. Scrape down the sides well, making sure to reach the bottom of the bowl. Turn the mixer on medium speed for 30 seconds.
Distribute the batter evenly between the mini bundt molds.
Bake until the a toothpick comes out of the center of one of the cakes, approximately 22 minutes. Allow the cakes to cool for ten minutes and then turn out onto a cooling rack. If the cake has risen above the top of the pan, use the underside of a baking sheet to gently press the cake into the molds before turning them out onto the racks. This will create a more dense cake.
Prepare the sauce:
Heat a medium saucepan with approximately 2-3 inches of water over high heat. Place a metal bowl on top of the saucepan and add the bittersweet chocolate, heavy cream and Chambord.
As the water boils and turns to steam, gently stir the ingredients together as they melt. If it looks like the sauce is getting too hot, remove the saucepan from the heat and allow the sauce to continue melting over the residual steam.
Serve over the chocolate cakes.
To melt the unsweetened chocolate for the cake, chop it and place in a small microwave safe bowl or cup. Microwave for 15-20 seconds at a time, stirring in between, until the chocolate is completely melted.