Cut the butter into cubes and let it sit at room temperature for 15 minutes until slightly softened. In a large bowl, beat the softened butter with the sugar for about 3 minutes until light and fluffy—this incorporates air into the dough and creates a tender cookie. Add the finely grated orange zest, fresh orange juice, vanilla extract, and room-temperature egg, then beat for another minute until fully combined. The mixture should look smooth and well-incorporated, with no streaks of egg or zest remaining visible.

In a separate bowl, whisk together the all-purpose flour, ground almonds, and salt. This ensures the leavening and salt are evenly distributed throughout the dry ingredients. Add the dry mixture to the wet ingredient mixture from Step 1 and fold together gently with a spatula or wooden spoon until just combined—don't overmix, as this can make the cookies tough. The dough should come together without any visible dry streaks and have a slightly crumbly, cohesive texture.

Divide the dough in half and wrap each portion tightly in plastic wrap. Refrigerate for 30 to 60 minutes until firm and easy to handle. I like to chill mine for the full hour when I have time, as it gives the flavors time to meld and makes the dough less likely to spread in the oven. You can prepare your baking sheets and oven while waiting.

Preheat your oven to 375°F. Remove one portion of chilled dough from the refrigerator and place it between two sheets of parchment paper. Using a rolling pin, roll the dough to a 1/4-inch thickness, working gently and evenly. The parchment paper prevents sticking and makes transferring the cookies to the baking sheet much easier. Repeat with the second portion of dough. If the dough becomes too soft while rolling, refrigerate it for a few minutes to firm up again.

Using a 2-inch round cutter, cut circles from both portions of rolled dough. From one portion, cut small circles from the center of half the cookies—these will be your 'window' cookies with cutouts. Leave the other portion whole; these will be your base cookies for sandwiching. Transfer all cut cookies to parchment-lined baking sheets, keeping the whole cookies and cutout cookies on separate sheets so they bake together without confusion.

Bake both sheets at 375°F for 11 to 13 minutes, until the edges are golden brown but the centers still have a slight pale color—this keeps them tender. Remove from the oven and let the cookies cool on the baking sheet for 2 minutes, then transfer to a wire rack to cool completely. Once cooled, dust the cutout cookies generously with confectioners sugar, which gives them a beautiful snowy appearance and adds subtle sweetness.

Spread about 1 teaspoon of maple frosting onto the flat side of each whole cookie. Place a cutout cookie on top, flat side down, so the frosting creates a seal between them and the pretty sugared window shows off the maple filling beneath. For a neater appearance, I like to apply the frosting in small dots around the edge rather than a thick layer in the middle—it gives you better control and prevents squishing.