Start by sifting together almond flour, powdered sugar, and cocoa powder into a large bowl. In a separate bowl, whisk egg whites at medium speed until foamy, then gradually add granulated sugar while increasing to high speed until stiff peaks form, about 5-7 minutes. Gently fold the dry ingredients into the meringue until fully combined, achieving a thick, shiny batter.

Line baking sheets with parchment paper or silicone mats. Transfer the macaron batter into a piping bag fitted with a round tip. Pipe 1.5-inch circles, leaving space between them. Once piped, tap the baking sheets firmly on the counter to release air bubbles. Let the macarons rest at room temperature for 30-60 minutes, until they form a skin and are no longer sticky to the touch.

Preheat the oven to 300°F (150°C) while the macarons are resting. Once dry to the touch, place the baking sheets in the oven and bake for 12-15 minutes. You’ll know they are done when they have a firm base (the “feet”) and can be lifted off the parchment easily. Allow them to cool completely on the sheets before attempting to remove them.

In a mixing bowl, beat together the softened butter and marshmallow fluff until light and fluffy, which should take about 3-5 minutes. The mixture should be smooth and creamy, perfect for spreading.

Select one macaron shell and generously pipe or spread the toasted marshmallow filling in the center. Top it with another macaron shell, sandwiching the filling inside. Continue this process until all the shells are paired with filling.

Using a kitchen torch, carefully toast the marshmallow filling until it's golden brown. If you don’t have a torch, you can also place the assembled macarons under a broiler for a few seconds, keeping a close eye to prevent burning.