Preheat your oven to 325°F (165°C). Lightly butter a 9-inch round cake pan and line the bottom with parchment paper.
In a large mixing bowl, cream the butter with both sugars until fluffy, about 3 minutes on medium speed.
Add the egg and yolk one at a time, mixing well after each addition. Stir in the red wine and vanilla extract (the batter may look a bit uneven—this is okay).
In a separate bowl, whisk together the flour, cocoa powder, baking soda, baking powder, salt, and cinnamon if using.
Add the dry ingredients to the wet in three additions, mixing until just combined. Do not overmix.
Pour the batter into the prepared pan and smooth the top.
Bake for 25–30 minutes or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Let the cake cool in the pan for 10 minutes before inverting it onto a rack to cool completely.
Dust with powdered sugar or top with whipped cream before serving, if desired.