01 -
Combine the granulated sugar and water in a small saucepan. Heat gently, stirring, until the sugar fully dissolves. Let the syrup cool completely. Reserve approximately one-third for the croissants, and refrigerate any leftovers for other culinary uses.
02 -
In a mixing bowl, beat the softened butter until creamy and smooth, about three minutes. Add the almond flour, powdered sugar, matcha powder, and salt. Mix until well combined. Incorporate eggs one at a time, blending thoroughly after each addition. Transfer the frangipane filling to a piping bag or a zip-top bag for assembly.
03 -
Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper. Slice each croissant horizontally. Place the bottom halves on the prepared baking sheet. Lightly brush the interiors of each croissant with the cooled simple syrup. Pipe an even layer of matcha frangipane onto each bottom half, then cover with the top halves. Pipe a decorative swirl or line of frangipane over the tops and press sliced almonds over the surface.
04 -
Bake the filled croissants for 20 to 30 minutes, or until golden brown and crisp. Midway through baking, loosely cover with aluminum foil to preserve the vibrant color of the matcha. Remove the tray from the oven and transfer croissants to a wire rack to cool for 10 minutes.
05 -
Dust the croissants generously with powdered sugar, or sifted matcha powder if desired. Serve warm or at room temperature for optimal flavor and texture.