In a large mixing bowl, whisk together the flour, cornstarch, powdered sugar, almond flour, baking powder, and salt until evenly combined and free of lumps.
In a separate small bowl or measuring cup, whisk together the melted coconut oil, coconut milk, vanilla, and almond extract (if using).
Pour the wet mixture into the dry ingredients and stir until fully combined. The dough should be soft and pliable - if it seems too dry or crumbly, add an extra tablespoon of coconut milk and mix again. Avoid over moistening.
Shape the dough into a flat disc, wrap it in plastic wrap, and chill for 10–15 minutes. Don’t chill for longer, or the dough may become too firm to roll. If it does firm up too much, let it sit at room temperature for a few minutes before using.
Preheat the oven to 350°F (175°C). Line two cookie sheets with parchment paper.
Roll the dough out between two sheets of parchment paper (not on a floured surface) to about ¼ inch (6mm) thickness.
Use a 2-inch (5cm) cookie cutter to cut out shapes. In half of the cookies, cut a small center hole using a ½–1 inch (1–2cm) round cutter or the wide end of a piping tip.
Gather and reroll dough scraps as needed, but avoid re-rolling more than once to prevent the cookies from becoming tough.
Place cookies 1 inch (2.5cm) apart on the prepared baking sheets. Bake for 9–11 minutes, or until the cookies are just dry to the touch and slightly golden around the edges.
Cool the cookies on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
Once cooled, dust the cookies with cut-out centers generously with powdered sugar. Flip the full-bottom cookies over and spread about 1 teaspoon of raspberry jam in the center. Top each one with a sugar-dusted cookie and press gently to sandwich.