For the Pretzel Crust

1. Line a 12-cupcake tin with liners.
2. Combine fine pretzel crumbs, melted butter, and granulated sugar together with a fork or spoon in a medium-sized bowl.
3. Evenly divide the crust into each cupcake liner, spooning about 1 tablespoon of the mixture into each cupcake cavity.
4. Push the crust down to flatten and firm it using your thumb or the back of a small spoon.

For the Cupcakes

1. Preheat your oven to 325 degrees Fahrenheit.
2. In a medium-sized bowl, whisk all purpose flour, sifted dark cocoa powder, baking soda, and salt until combined.
3. In a large bowl, whisk vegetable oil, room temperature sour cream, granulated sugar, room temperature eggs, vanilla extract, and buttermilk until fully combined.
4. Bring water to a boil in a small saucepan over medium heat.
5. Alternate adding the dry ingredients and boiling water to the bowl of wet ingredients, starting and ending with the dry ingredients. To do this, add 1/2 of the dry ingredients to the wet ingredients, and whisk for about 5 seconds before adding 1/2 of the boiling water. Whisk in 1/2 of the remaining dry ingredients to the batter before adding the remaining boiling water. Add final portion of dry ingredients to the batter, and mix until the dry ingredients are just incorporated. Make sure there are no pieces of unmixed dry ingredients. Batter will be very thin.
6. Divide batter between the 12 cupcake cavities- somewhere between 1/4 cup and 1/3 cup of batter. The batter should almost fill the liners, especially with the pretzel crust underneath.
7. Bake cupcakes for 18-23 minutes. If you have an uneven oven, turn your tin at the 17 minute mark, as turning earlier will risk deflating the cupcakes. Cupcakes should bounce back when poked in the center, and a toothpick inserted into the center will come out with just a few crumbs.
8. Let cupcakes cool for about 20 minutes before frosting.

For the Salted Caramel Buttercream + Decoration

1. If using a hand mixer, bring your butter to room temperature before making the frosting. To do this, simply leave your butter out on the counter 1-2 hours before baking. If you forget, cut your butter stick into 1-tablespoon sized pieces. Microwave the pieces laying flat for 10 seconds before flipping the pieces over and microwaving for another 10 seconds. Repeat the process in 5 second increments until the butter is soft but still cool to the touch. You should be able to make an indent without breaking through the butter piece when sticking your finger in it.
2. If using a stand mixer, fit it with your paddle attachment. Beat cold butter until smooth- about 2 minutes of mixing.
3. Slowly, add your powdered sugar to the butter on low speed. Beat the butter and sugar together for 3 minutes on high speed.
4. Add room temperature caramel sauce to your buttercream while mixing on low speed. Mix on high speed for an additional 2-3 minutes until the buttercream is light, fluffy, and velvety.
5. Frost cupcakes as desired before decorating with crushed pretzel pieces and topping each cupcake with a whole mini pretzel.