Giant Nutella-filled cookies

Make hazelnut butter from toasted hazelnuts.

Bring heavy cream and corn syrup or glucose (or honey) and simple syrup to a boil.

Pour the hot mixture over milk and dark chocolate, let stand a minute to melt, blend well, then blend in the hazelnut butter to a good emulsion.

Fill half-sphere cavities with the spread and freeze overnight.

Mix softened butter and salt, then add white and brown sugar and mix well; add eggs one at a time, smooth between each addition. Warm over the stove if too firm; aim for a buttercream texture.

Add sifted flour, baking soda and toasted hazelnut meal; scrape down the bowl.

Add crushed hazelnuts and large pieces of chopped bittersweet chocolate; mix on low until just combined.

Sandwich each frozen Nutella insert in cookie dough, with or without a tart ring.

Freeze 30 minutes, then bake.