Preheat oven to 325 degrees F. Liberally spray a 12-cup Bundt® pan with non-stick baking spray or prepare with shortening/butter and flour.
Add melted butter to bottom of the bundt pan then cover butter with 3/4 cup of the brown sugar.
Evenly sprinkle cranberries, raspberries and pomegranate seeds over the brown sugar covering entire area then carefully pat down inside the pan.
Cover berries with the remaining 1/4 cup of brown sugar.
For the Cake Batter
In your mixer bowl, add butter and beat on high speed for 1 minute. Slowly add in sugar and mix on high speed for an additional 5 minutes until very pale yellow and fluffy.
Next, add eggs, one at a time, combining well after each addition and scraping down the sides as needed.
Whisk together flour, cinnamon and salt in a medium sized bowl. Turn your mixer down to its lowest speed, and slowly add flour mixture into batter in two increments. Be careful not to overbeat.
Lastly, add sour cream and vanilla extract, scrape down sides, and mix until just combined and turn off mixer.
For the Swirl
Remove 1 cup of cake batter from mixing bowl and add to separate small bowl.
Stir in melted raspberry jam and red food coloring and whisk until smooth.
Evenly spread 1/3 cake batter into bundt pan over berries then add 1/2 of swirl batter over the top.
Repeat step by adding 1/3 of cake batter and remaining swirl batter on top.
Finally, add remaining 1/3 of plain batter to the top.
Bake for 1 hour and 15 to 25 minutes or until toothpick inserted into the top of cake comes out clean. Tip: Add a sheet of parchment paper or foil on a shelf below the bundt pan to catch any juices that may drip during baking.
Remove cake from oven and cool for only 5 to 7 minutes in pan. Carefully invert cake onto serving plate to finish cooling. If any berries stick to pan, carefully use a butter knife to remove and place back on the top of the cake. Let the juices settle (to speed this process you can refrigerate).
Garnish with a small sprinkling of powdered sugar, if deisred.