Paris-Brest

Melt 120g butter, then mix with 190g flour, 250g beaten eggs, and 4g powdered sugar until smooth.

Pipe choux paste in a large ring onto parchment paper; bake at 200°C for 35–40 minutes until golden.

Heat 103g milk with 100g butter; whisk in 80g flour and 30g cornstarch, stirring until thickened, then cool.