Preheat the oven to 350 degrees F. Line a standard muffin tin with paper liners, or spray with nonstick cooking spray. If using paper liners, I like to spray the inside slightly with nonstick cooking spray to ensure the muffins don't stick to the paper.

In a medium size bowl, combine the eggs, milk, sour cream, brown sugar, vanilla extract, and melted butter. whisk to combine thoroughly.

In another medium size bowl, combine the all purpose flour, polenta, kosher salt, baking soda, and baking powder, whisk to combine. Add the wet ingredients to the dry ingredients, and use a wooden spoon to combine, until there are no dry patches of flour, scraping the bottom of the bowl as you gently mix. The batter should be thick.

Use a small ice cream scoop to scoop about 2 tablespoons of batter into the bottom of each prepared muffin cup, filling the cup about halfway full. Then spoon a generous tablespoon of strawberry preserves on top of each. Fill the cups with the remaining batter. The muffin cups will be very full, that's ok!

Bake for 35-40 minutes, or until golden brown, and the centers are completely set.

Allow to cool for 5 minutes, and enjoy right away!