Preheat oven to 350 and liberally grease a loaf pan. Alternately you can line the pan with parchment paper, leaving a 1" overhang on all sides.
In the bowl of a mixer, cream together butter and sugar. Beat in eggs 1 at a time until both are incorporated. Mix in vanilla and strong brewed coffee.
In a small bowl, combine sour cream and heavy cream together. Add to the mixing bowl and beat together just until incorporated
In a large bowl, whisk together the flour, cocoa powder and baking soda.
Slowly add dry ingredients to mixing bowl, and blend together just until mixed. Do not over mix the batter.
Pour batter into prepared loaf pan. Bake for 35-45 minutes or until a toothpick inserted in the center comes out clean.
When finished baking, let cool for 15-20 minutes. Then gently run a spatula around all edges of the cake to release from pan. Gently turn out onto a plate or baking sheet to let it cool the rest of the way. *if you used parchment paper, gently lift out the parchment paper by the 1" over hang. Peel it away from the cake and leave it to cool the rest of the way.
Peppermint Cream Cheese Glaze
Cream together the softened cream cheese, butter, heavy cream and peppermint extract.
Slowly whisk in the powdered sugar until desired consistency is reached. The glaze should be thin enough to pour easily. If too much sugar is added, thin out the glaze with 1 tbsp of heavy cream at a time until desired thickness is achieved.
Pour the glaze onto the cooled dark chocolate loaf cake. Start at one end and slowly dribble back and forth until reaching the opposite end.
Top with crushed peppermint candies and sprinkles if desired.