Preheat the oven to 350 degrees.
Combine brown sugar, butter and maple syrup in a small pot and stir continuously until the butter has melted.
Add the cranberries and cinnamon and let the mixture simmer for at least 10 minutes. Continue stirring frequently.
While the cranberries cook down combine your dry ingredients for the cake in a separate bowl.
Add the butter, milk, sour cream and eggs and mix well. I use a hand mixer but you can also use a stand mixer.
Last add the cinnamon and vanilla and mix thoroughly.
Butter a 9-inch, round cake pan. Make sure you coat the sides well.
Add your cranberry mixture to the bottom of the pan. Tap it lightly a few times on the counter so that you can even it out.
Add your cake batter on top of it and again even out the batter.
Put the cake in the oven for 50 minutes and then check it. You might need another 10 minutes to cook it through the center.
Once the cake is done let it cool completely. Then run a knife around the sides of the pan to make sure the cake isn’t sticking to it.
Add a plate or cake stand to the top of the cake and then flip it. Just get help if you plan to use a cake stand.
If it doesn't come out of the pan perfectly and you're missing some cranberries at the top, top it off with some extra cranberry sauce.