Put the flour, cinnamon, baking powder and sugar in the bowl of a stand mixer fitted with a dough hook, and mix together on medium speed. Add the butter and mix until crumbly. Add the vanilla and 120ml water, and mix again until everything comes together into a dough. Knead the dough for 5 mins until smooth, then transfer to a bowl and cover with plastic wrap. Leave to rest for 15 mins.

Divide the dough into 18 pieces. Lightly flour a work surface and roll each piece of dough out into a 5in disc.

To make the topping, combine the cinnamon and sugar in a small bowl. Heat the oil in a heavy, deep frying pan over a medium-high heat until a small piece of dough sizzles and rises to the top when dropped in. Carefully put one of the dough discs in the hot oil and use metal tongs to submerge it. Fry for 2-3 mins until golden, then transfer to a cooling rack set over a cookie sheet to drain. Sprinkle some of the cinnamon sugar on both sides. Repeat with the remaining dough discs and cinnamon sugar, then serve immediately.