I highly recommend making the salted caramel and the brown butter for the buttercream the night before so that they both have time to fully cool!
Warning: do not walk away from your caramel because it will probably burn the second you walk away from it (trust me).
In a heavy bottomed saucepan over medium heat, add the sugar and stir every 1-2 minutes or so until it begins to melt (the sugar will start to clump up before melting).
Once the sugar is completely melted and smooth (it should be an amber color), immediately remove from the heat and stir in the butter until combined (don’t be scared if it bubbles a lot).
Add in the heavy cream and salt and mix until fully combined and smooth. It won't want to combine at first, but just keep stirring and it will come together.
Pour the caramel into a heavy glass jar to cool to room temperature. Can be stored in the fridge for up to a month!
If you make the caramel the night before, it can sit covered at room temperature overnight so that it's a nice pourable consistency.
Preheat the oven to 350°F and line a 12 cup muffin pan with cupcake liners.
Whisk the cake flour, almond flour, baking powder, and salt together in a large bowl.
In a separate bowl, whisk the brown butter, sugar, eggs, vanilla, and almond extract together until combined.
Stir in about half of the flour mixture. Then stir in the milk and the rest of the flour mixture and mix until fully combined. The batter will be thin.
Pour about ¼ cup of batter into each cupcake liner (they should be about halfway full).
Bake at 350°F for 18-22 minutes or until a cake tester comes out clean.
Remove from pan and let cool on wire rack.
Let cupcakes cool completely before frosting.
Salted Caramel Buttercream
In a large bowl using a handheld or stand mixer fitted with a paddle attachment, cream the butter until smooth.
Add in the powdered sugar ½ cup at a time until fully combined and smooth.
Set the mixer to low speed and slowly drizzle in the salted caramel until it's fully incorporated into the buttercream. Then beat on high speed for 3-4 minutes or until the buttercream is super light and fluffy.
If needed, add in milk 1 teaspoon at a time until desired consistency is reached.
Frost cooled cupcakes. I used a Wilton 1M tip for these photos. Then drizzle with extra salted caramel.
These cupcakes will last in the fridge for up to 3 days. However, they taste best when served at room temperature! I like to let them sit at room temperature for about an hour before serving.
Brown the butter: In a small saucepan, melt butter over medium heat. Once melted, stir frequently and watch closely for the formation of brown specs on the bottom of the pan and a nutty aroma. Once you see brown specs, stir for just a few more seconds (it browns super quickly). Remove from the heat and immediately pour into a different bowl to prevent it from burning. Let cool for 5-10 minutes for the cupcakes and fully to room temperature for the buttercream. Note: For every ½ cup (1 stick or 113g), you'll lose about 1 tablespoon (14g) to evaporation while cooking. So you can either add in an extra 1 tablespoon before browning, or if you're browning big batches, just make up the weight difference in your recipe with regular unsalted butter if needed.