Preheat the oven to 350F (180C)

Spread the almonds on a baking sheet and roast in the oven until they are lightly browned.
Cook the sugar in a thick-bottomed saucepan over low heat, stirring gently and continuously with a spatula, until it is golden caramel-colored.
Add the almonds and mix over low heat for 1 minute, then add the butter and mix until it is fully absorbed. (This is not essential, but it will give the nougatine a glossy finish).
Pour the nougatine onto a greased pastry sheet.

Wait a few seconds before cutting the nougatine into triangles.
As soon as possible, while the nougatine is still warm but pliable, fold two points of the triangles over each other to form a kind of pointed cone.

Let it cool completely before using to fill with ice cream.