Ingredients
Method
Start by making the caramel sauce
- Note before starting the caramel: caramel can be very tricky, so make sure you read through the instructions before beginning.
- Microwave the heavy cream and butter separately in two bowls for 20 seconds. They should be slightly warm but not hot.
- In a medium sized saucepan over medium heat melt the sugar, stirring occasionally. It can take up to 20 minutes to melt, so don't be alarmed if it doesn't look like it's doing anything. Once it's mostly melted, make sure you're stirring constantly to make sure it doesn't burn while you're waiting for the last few lumps to melt down.
- Once the sugar has completely melted, whisk in the butter. It will splatter and sizzle, so be careful! You may have to remove the caramel from the heat briefly and whisk vigorously to get it to come together. Still whisking, stream in the heavy cream (again being careful of the splashing). You should have a smooth and thin caramel. Stir in the vanilla extract and salt.
- Pour the caramel through a sieve (to remove any chunks of crystallized sugar) and into a bowl. Let the caramel cool uncovered for 10 minutes or so before covering with cling wrap and letting it cool at room temperature while we make the rest of the cupcakes.
Make the cupcakes
- Start by browning the butter. Melt the butter over medium heat in a medium sized saucepan. Once melted, start stirring constantly and the butter will begin to sizzle and foam, and you will then start to see brown specks forming. Keep cooking until the butter has turned a caramel brown color. Pour into a bowl and place in the freezer to solidify partially while we make the rest of the cupcakes.
- Preheat the oven to 350℉ and line a 12 count cupcake tin with liners. Line a second pan with two liners. This recipe makes about 14 cupcakes.
- In a food processor, pulse the pistachios until they reach a fine consistency, similar to that of almond flour. We will use ¾ cup of this in the actual cupcakes, but save the remainder to use in the caramel shards if making.
- In a medium sized mixing bowl, whisk together ¾ cup of the ground up pistachios, cake flour, baking powder, baking soda, and salt. Set aside.
- In a large mixing bowl using a hand or stand mixer fitted with a paddle attachment, beat together the cooled down (and slightly solidified) brown butter and granulated sugar on medium speed until fluffy and combined. Add the egg whites, vanilla, and pistachio extract and mix on medium speed until smooth. Finally, mix in the sour cream. With the mixer running on low speed, mix in all of the dry ingredients until almost combined. With the mixer still running on low speed, stream in the whole milk and mix until just combined. The batter will be fluffy and slightly thick.
- Scoop the batter into the cupcake liners, filling almost all the way to the top. Bake for 20-22 minutes or until the cake bounces back when lightly poked, and an inserted toothpick comes out clean. Let the cupcakes cool completely in the pans set on a wire cooling rack.
Make the caramel shards (optional topping)
- Line a baking sheet with parchment paper and set aside. Get out all the ingredients for the caramel so they are at the ready.
- In a medium sized saucepan, melt the sugar over medium heat until amber brown, for roughly 6 minutes. It will seem like nothing is happening at first, but the sugar will begin to melt and clump up, and will eventually all melt down to a deep amber brown. Once melted, add the butter and use a whisk to combine. Once butter is completely melted, remove the saucepan from the heat and whisk vigorously just until the butter is mostly combined. Then immediately pour the caramel onto the previously prepared baking sheet and spread it out into a relatively thin layer. It hardens fast, so work quickly! While it's still hot, sprinkle with leftover pistachio crumbs. Let the caramel sit for 5 minutes before using your hands to break it into small shards. Set aside until ready to use,
Make the frosting
- Using a hand or stand mixer fitted with a whisk attachment, beat the butter on medium speed until smooth and creamy, about 1 minute. Add in the sugar, baileys, coffee, espresso powder, vanilla extract, and salt, and mix on low speed until mostly combined before turning up to high speed to whip until fluffy and creamy. Make sure you don't overman the frosting, or it may split.
Assemble
- Fill the cupcakes with the cooled caramel. Using a sharp knife, cut a circle into the center of the cooled cupcakes to create a pocket a little over 1 inch deep. The piece you remove will be cone shaped, so cut off the pointed end but keep the round "hat". Spoon a loaded teaspoon of the cooled caramel into the hole to fill to the top, and top with the round part you cut out to seal the hole. Repeat with the remaining cupcakes.
- Using a piping bag fitted with a piping tip (I used Wilton 4B), pipe a spiral of the frosting on top of each cupcake. Top with the caramel shards and leftover pistachio crumbs. Cupcakes stay fresh for up to 4 days in an airtight container in the refrigerator.