01 -
Preheat oven to 200°C/390°F. Line baking sheet with parchment paper.
02 -
Whisk flour and cocoa powder together in bowl. Set aside.
03 -
Melt butter and oil in saucepan. Add water, brown sugar, food coloring, and salt. Bring to boil for 5 minutes.
04 -
Add flour mixture to liquid, stirring until well blended. Cool 10 minutes.
05 -
Add vanilla and egg, beat quickly until incorporated (keep beating even if it looks separated).
06 -
Transfer to piping bag with large star tip. Pipe 4-inch strips onto baking sheet. Bake 10 minutes, then reduce oven to 175°C/350°F and bake 7-10 minutes more.
07 -
Immediately coat warm churros in caster sugar. Serve with Nutella or chocolate of choice.