Preheat the oven to 350 degrees F. Spray a mini heart cake pan with non-stick cooking spray and set it aside.
Mix the flour and baking soda. Add the peanut butter, vanilla, honey and oil/butter and stir. Add the buttermilk, 1/4 cup at a time. Stir in carrots.
Spoon the mixture into the mini heart cavities, filling each one three-quarters full. Bake for at least 25 minutes or until an inserted toothpick comes out clean. Let cool completely.
While the cakes cook, prepare frosting by beating the cream cheese, vanilla and cinnamon together. Once the cakes have cooled, frost. Drizzle melted peanut butter on top or top with additional shredded carrots.