Preheat oven to 350 F. Line a cupcake tin with paper liners.
1. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and brown sugar until fluffy, 2 minutes.
2. Add the eggs, one at a time, and turn mixer up to medium. Beat for about 5 minutes, until pale and creamy.
3. In a small bowl, sift together dry ingredients. In a second small bowl, whisk together sour cream and vanilla.
4. Add 1/3 of dry mixture into the egg and butter mix; blend lightly. Add 1/2 of the dry ingredients, mixing on low until almost incorporated. Repeat this alternation, ending with the last 1/3 of the dry ingredients.
5. With mixer on low, slowly pour hot water into batter in a gradual stream, stopping to scrape the sides of the bowl with a spatula every once in a while. Once fully incorporated, divide batter evenly in prepared cupcake tin.
6. Bake until cakes spring back when touched, about 25-30 minutes.
1. Pour sugar into a heavy-bottomed saucepan and cover with just enough water to saturate the sugar. Place on stove over medium-high heat and cook until it reaches the soft-ball stage, about 240 F.
2. Meanwhile, while sugar cooks, place egg whites into a clean bowl of a stand mixer fitted with the whisk attachment. Whip on high until soft peaks form. If soft peaks form before syrup is ready, turn mixture on low.
3. Once syrup is ready, pour into egg whites in a slow and gradual stream, with mixer on medium. Once all syrup is in, continue to whisk on medium for about 5 minutes, or until mixture has cooled slightly.
4. Start adding in soft butter, about a tablespoon at a time, until all the butter is in. Allow to beat a few more minutes until buttercream is silky and smooth.
5. Add elderflower bourbon until mixed.
Frost cupcakes as desired with elderflower buttercream. Top with candied elderflowers.
Will store great in fridge for about 3 days; allow to warm to room temperature before eating for best texture and flavor.
Note: Check out this post for recipes for elderflower bourbon & candied elderflowers.
