7/8 c flour
3/8 c cocoa powder
3/4 tsp baking soda
1/4 tsp salt
4 Tbls butter, softened
1/4 c sugar
1/4 c brown sugar
1 egg yolk
1/2 tsp vanilla
1/2 c milk
Preheat the oven to 350F and line 2 baking sheets with parchment paper. Set aside.
Place the flour, cocoa powder, baking soda and salt in a small bowl. Whisk well to combine and set aside.
In a medium-sized bowl, beat the butter until lightened, about one minute. Add the sugars and beat until fluffy, about 3 minutes. Add the yolk and vanilla and beat to combine, scraping down the sides of the bowl when necessary.
Pour in 1/3 of the dry mixture and mix on low speed until just combined. Scrape down the bowl and add half of the milk, mixing just to combine. Continue alternating, ending with 1/3 of the dry ingredients.
Using a tablespoon-sized scoop, drop the cookies onto the prepared baking sheets, spacing them about 2 inches apart. Bake 10-15 minutes until the top springs back when pressed. Cool completely on pans before sandwiching with the filling (recipe follows).
Salted Caramel Swiss Meringue Buttercream
1/2 c sugar, divided
1 Tbls corn syrup
2 Tbsp water
2 Tbsp + 2 tsp (40 mL) cream
2 egg whites
1/4 tsp salt, to taste
1/2 c butter, softened
1/2 tsp vanilla extract
Put 1/4 cup of sugar, the corn syrup and the water in saucepan over medium-high heat. Swirl the pan occasionally (but do not stir) until the sugar is dissolved, then continue cooking until the sugar reaches an amber color. Remove the pan from the heat and pour in the cream, whisking immediately as it will begin to bubble. Set aside to cool.
Place a pan of water over medium-low heat and bring to a simmer. Put a medium-sized heatproof bowl over the top (do not let it touch the water) and pour the remaining 1/4 cup of sugar, egg whites and salt into it. Whisking constantly, cook until the sugar has dissolved then remove from the heat. Whip on high speed until a stiff meringue forms. Reduce the speed to medium and begin adding the butter in tablespoon-size pats, waiting until each has been fully incorporated before adding the next, about ten seconds. When all of the butter has been added, raise the speed to high and whip until the frosting is light and fluffy. Add the cooled caramel and vanilla, then whip to combine. Use to fill cooled cookies.
Put the egg whites, salt, and 1/4 cup sugar in a heatproof bowl over a pot of simmering water. Whisk until sugar dissolves and mixture reaches 140 degrees. Transfer to bowl of standing mixer.
3. Beat on high until stiff peaks form. Add butter a bit at a time, and continue beating on medium. Reduce speed to low, add vanilla extract, and then caramel (you may need to gently rewarm the caramel in the microwave for 10 seconds at a time until it is workable but not burning hot). Beat for 4-5 minutes.