Step 1

In a small saucepan, melt the butter.

Step 2

Add the light brown sugar and salt, and whisk until the mixture simmers. Continue to whisk for 1 more minute then transfer to a bowl.

Step 3

Add the vanilla and ground almonds and mix well. Let the mixture sit and cool for a few minutes.

Step 4

Add the egg white and 1 Tbsp water. Mix well. The mixture should be liquid, not hard, so add another Tbsp water if needed.

Step 5

Let the mixture cool for 10 minutes. Meanwhile preheat your oven to 180°C/ 350°F.

Step 6

On a sheet tray lined with a baking sheet, place 1 tsp of the mixture at a time, leaving 4-inch gaps between each cookie, as the mixture will spread.

Step 7

Bake for 7-9 minutes. When the butter stops bubbling and the cookies are caramelized, they are done. Remove from the oven and let the cookies cool completely on a wire rack.

Step 8

When the cookies are cool, pair them up, and fill each sandwich with Nutella or filling of your choice.