Double chocolate mini egg sandwich cookies

Directions

Vanilla Bean Buttercream

1. Fill a medium saucepan with two to three inches of hot water as part of a double boiler and bring to a boil over high heat. Once boiling, reduce the heat to low to maintain a simmer.
2. In a medium glass or stainless steel bowl that will fit nicely over the pan of hot water but not touch the simmering water below, whisk together the egg whites, sugar, and salt. Place the bowl over the simmering water bath. Whisk constantly until the sugar has dissolved and the mixture has a sticky, tacky-looking texture. As it is heating, you will notice the mixture becoming more fluid; keep whisking until it reaches 140°F (60°C) on a candy thermometer, or until the mixture is body temperature to the touch and the sugar is dissolved.
3. Transfer the meringue mixture to the bowl of a stand mixer fitted with the whisk attachment. Whisk on high speed for 10 to 15 minutes, or until stiff peaks have formed and you can no longer feel any heat coming from the bottom of the mixing bowl.
4. Reduce the speed to medium-high and start adding the butter pieces, waiting until each addition is fully incorporated before adding the next. Scrape down the sides of the bowl at least twice while making your additions.
5. Once all the butter is incorporated and the buttercream is smooth, beat for five minutes on high speed. Give the bowl one final scrape, then add the vanilla extract and paste and continue to beat on high speed for two more minutes.
6. Use immediately or keep covered at room temperature for up to one day until ready to use. When ready to use, in the bowl of a stand mixer fitted with the paddle attachment, beat on high speed for five to 10 minutes.

TIP: Store in an airtight container in the refrigerator for up to two months or in the freezer for up to six months. If refrigerated, let soften at room temperature. If frozen, thaw in the refrigerator overnight. When ready to use, in the bowl of a stand mixer fitted with the paddle attachment, beat on high speed for five to 10 minutes.

Milk Chocolate Ganache 

1. Combine chocolate, whipping cream, and corn syrup in a small heat-resistant bowl and heat in the microwave for 30 seconds. Vigorously stir until the ingredients are incorporated and the mixture is glossy and smooth. TIP: If you see any lumps, heat in the microwave in 15-second intervals, stirring after each interval, until smooth. Set aside. 

Cookies 

1. Preheat the oven to 350°F (180°C). Line 2 baking sheets with parchment paper or silicone baking mats.
2. Make the cookies: Sift the flour, cocoa, and baking soda into a medium bowl.
3. In a large bowl, whisk together the melted butter, granulated sugar, brown sugar, and salt until the mixture is smooth and no oily film remains around the edges. Whisk in the egg and vanilla until the mixture is smooth and light in colour.
4. Using a spatula, stir in the flour mixture, chocolate chunks, and mini eggs and mix until no dry flour remains. The dough may look a little wet, but it will firm up as the butter cools.
5. Scoop six three-tablespoon portions of cookie dough onto each baking sheet, leaving ample space between them. Bake, one sheet at a time, for 15 to 18 minutes, or until the cookies are puffed up and appear dry on top. Allow the cookies to cool on the baking sheets.
6. Ice the cookies: Place half of the cookies, upside down, on a clean baking sheet. Set aside the remaining six cookies; these will be the tops. In the bowl of a stand mixer fitted with the paddle attachment, beat the vanilla bean buttercream until light and fluffy, seven to 10 minutes. Using a small offset palette knife, smooth one tablespoon of buttercream on each cookie, leaving a half an inch border of exposed cookie around the edge. This is to prevent the bottom cookie from getting soggy after you add the filling. 
7. Pipe the iced cookies: Fill a 16-inch piping bag fitted with a No. 824 star tip with the remaining vanilla bean buttercream. Pipe a thick circle of buttercream onto each iced cookie to create a well for the filling, leaving a one-quarter-inch border of exposed cookie around the outer edge 
8.  Coat the cookies with crushed mini eggs: Fill a medium bowl with the lightly smashed mini eggs for coating. Scoop a palmful of crushed mini eggs in your dominant hand. Hold the cookie in your other hand and, working over the bowl to catch any bits that fall, gently push and coat the sides of the icing with the crushed mini eggs while rotating the cookie. Create an even crust around the buttercream border.
9. Fill the wells with ganache: Place the milk chocolate ganache in a small heat-resistant bowl and heat in the microwave in 15-second intervals, stirring after each interval, until the ganache has a pourable consistency but is not warm enough to melt the buttercream. Fill each well with two tablespoons of ganache, being careful not to go above the top of the buttercream border. 
10. Top and form the sandwich cookies: Place the remaining cookies on top of the filled cookies to form sandwiches. Using even pressure, gently push down on the tops to form a bond with the filling. Serve and enjoy!