Put the blueberries and maple syrup in a small pot then bring to a simmer. Simmer for 10 to 15 minutes, or until reduced down and syrupy, stirring occasionally. Remove from heat. Stir in the vanilla, cinnamon, and salt, to taste.
While the syrup is cooking, heat a medium cast iron or nonstick skillet over medium heat with the oil, if needed. Pat the polenta slices dry with a paper towel. Cook the polenta slices for 5 minutes on each side or until crispy and hot.
Place the cooked polenta on a plate, then top with the syrup, butter, peanut butter, fresh fruit, and hemp hearts, if using.
