Toasted Vanilla Bean Shortbread with Malted Cream Filling

1. Toast the Flour:
Preheat the oven to 350. Line a rimmed baking sheet with parchment paper. Add 1 ¾ cups all purpose flour and spread out over the parchment evenly. Bake, stirring once every 10 minutes or so, until the flour smells toasty and is light tan in color, about 20-35 minutes. Let cool on the baking sheet.
2. Make the dough:
In a large bowl with electric beaters, or the bowl of a stand mixer, combine 2 sticks (16 tablespoons) unsalted butter and 1 ½ cups plus 2 tablespoons powdered sugar. Beat on low, increasing to medium as the sugar incorporates, and scraping sides of the bowl as needed until smooth and pale yellow, about 2 minutes.
Add 2 egg yolks, 2 tablespoons vanilla bean paste (or extract) and beat again until combined, 30 seconds.
Add the toasted flour (all at once), and 1½ teaspoons salt. If you have a sifter and want to sift the flour into the bowl, it will make for an even smoother cookie with a finer crumb, but by no means is that necessary. Beat on low until just combined.
Divide the dough into two equal portions, gathering it into a rough ball shape, on two separate sheets of parchment. Top each dough ball with a second piece of parchment and carefully roll out to about ¼” thick. Once both sheets are evenly rolled, place on top of one another on a rimmed baking sheet and transfer to fridge to chill until hard, at least 20 minutes and up to overnight. A few minutes before you are ready to bake, arrange racks in the center of your oven, and preheat the oven to 350.
3. Meanwhile, make the ganache:
While the dough chills, chop 7 ounces white chocolate until no pieces are larger than a chickpea. Transfer to a small-ish heatproof bowl.
In a small saucepan, combine 1 ¼ cups heavy cream, ¾ cup malted milk powder, ¾ teaspoon salt and 1 ½ teaspoons vanilla bean paste or extract. Set over medium heat and bring to a simmer, whisking occasionally. Once the edges simmer, pour the hot cream mixture over the chocolate and stir well until all the chocolate has melted and the mixture is creamy and smooth.
Place a piece of plastic wrap on the top of the ganache to prevent a skin from forming and chill several hours, until thick but pourable. You can speed this process up by starting it in the freezer for about 45 minutes and then transferring to the fridge. It should not be liquidy once cold.
4. Cut and bake:
Line two baking sheets with parchment paper.
Using a sharp knife, cut the cookie dough into triangles (or really any shape you like!) by making parallel cuts about 3” apart, and then cutting those strips into triangle shapes. The most important part here is consistency in size because we are going to stack the cookies to sandwich them together. So whatever size or shape you end up with, just make sure they are consistent by using a ruler. Carefully transfer the cookies to the lined parchment sheets using a spatula, and spacing them out about an inch or so apart (they don’t spread a ton). You may need to bake in two rounds of 2 sheets, and can absolutely re-roll scraps if you’d like. To half of the cookies, use a sharp paring knife to cut out and remove a triangle or circle shape (this way the ganache filling will peek through like the photo.
Bake, rotating the sheets 180 degrees halfway through until no longer wet, and just set with light browning at the edges, but NOT deeply golden brown all over, 10-12 minutes. They’re more delicious and nuanced when they aren’t super well toasted. As soon as they come out of the oven, generously sprinkle the tops with granulated sugar.
Let cool slightly before transferring to a wire rack to cool completely.
Bake the remaining round of cookies in the same manner.
5. Fill and sandwich:
Once cool, add a quarter sized dollop of ganache to the center of the bottom halves of the cookies (flip them upside down so you’re adding the ganache to the unsugared side), that way the sugar is on the outside. Add the top cookie and gently press to adhere. Let set at room temperature at least 1 hour before serving!
Keep cookies sealed in an airtight container at room temperature for up to 3 days.