In a small saucepan, add the butter and place over medium heat. As the butter melts, stir it with a rubber spatula to encourage even cooking. Once the butter has fully melted, it will alternate between rapid large bubbles and gentle small foamy bubbles. The butter will be ready once it turns a dark golden color and the fat solids have darkened and settled at the bottom of the pan.

To the brown butter, slowly pour in the heavy cream and stir to combine. Set aside until ready to use.

In a separate small saucepan, combine the sugar, salt, cream of tartar, and water. Place over medium high heat, stirring often with a rubber spatula to encourage even cooking.

When it comes to a boil reduce the heat to medium and continue stirring often. After about 10 minutes, when the color turns an even medium amber color, slowly stream in the butter heavy cream mixture, quickly mixing until fully combined. Continue cooking and stirring with the rubber spatula for one more minute.

Remove the caramel from heat, mix in the vanilla, then and pour into a glass jar. Stir in a pinch or two of flaky sea salt, then chill in the fridge overnight or until ready to use.

Preheat the oven to 350 degrees F and add parchment cups to a cupcake pan.

In a large bowl, whisk together the flour, baking powder, salt, and spices. Set aside.

Brown the butter: In a small saucepan, add 155g (11 tbsp) of salted butter and place over medium heat. As the butter melts, stir it with a rubber spatula to encourage even cooking. Once the butter has fully melted, it will alternate between rapid large bubbles and gentle small foamy bubbles. The butter will be ready once it turns a dark golden color and the fat solids have darkened and settled at the bottom of the pan. Immediately pour into a large bowl, scraping out the fat solids at the bottom, and weigh out to 113g (½ cup).

To the brown butter, whisk in the sugars, then the eggs, vanilla, and molasses until fully combined.

Then, mix in half of the dry ingredients until barely combined, followed by the applesauce. Add in the remaining dry ingredients and gently fold with a rubber spatula until just combined.

Lastly, fold in the grated apples until evenly dispersed.

Transfer the batter to the cupcake pan, filling each cup about ¾ full.

Bake the apple cupcakes for about 20 minutes or until a toothpick inserted comes out clean. Allow the cupcakes to cool in the pan for a few minutes before transferring to a wire rack to cool completely.

In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and cream cheese on high speed until smooth.

Slowly add the sifted powdered sugar and mix on low speed until fully combined.

Drizzle in the caramel sauce and continue beating on low speed until no more lumps or pockets of air remain and the frosting is smooth.

Decorate the cupcakes as desired.