Preheat your oven to 300°F (150°C). In a mixing bowl, whip egg whites with cream of tartar until foamy. Gradually add granulated sugar until stiff peaks form.

Sift together almond flour and confectioners' sugar, then fold into meringue being careful to maintain volume.

Perform the macaronage technique until the batter reaches a shiny, flowing consistency.

Pipe 1.5-inch circles on a baking mat, sprinkle with crushed graham crackers, and let rest for 60 minutes.

Bake for 19-23 minutes until tops are firm, then let cool completely on the mat.

For ganache, heat heavy cream until steaming, pour over chocolate and butter, whisk until smooth, then chill until firm.

Combine butter and marshmallow fluff until fluffy, gradually add confectioners' sugar, vanilla, and salt.

Assemble macarons by piping buttercream on one shell, adding ganache, and topping with another shell.

Store assembled macarons in an airtight container in the refrigerator for at least 1 day before serving.