In a mixing bowl, sift together almond flour and powdered sugar. In a separate bowl, whip egg whites until foamy. Gradually add granulated sugar until stiff peaks form, about 5-7 minutes. Gently fold in the almond flour mixture.

Transfer batter to piping bag. On a parchment-lined baking sheet, pipe small rounds about 1.5 inches in diameter. Let rest at room temperature for 30-60 minutes until tops feel dry.

Preheat oven to 300°F (150°C). Bake macarons for 15-18 minutes until feet form and they do not stick to parchment.

Melt butterscotch chips in a microwave-safe bowl until smooth. Mix melted butterscotch with room temperature butter and butterscotch flavoring until creamy.

Pipe filling onto one macaron shell and top with another shell to create a sandwich. Repeat with remaining macarons.