Heat a wide, deep frying pan over medium heat. Add the butter, once melted add the onion and garlic, cook stirring until the onion turns translucent. Add the tomato paste, chilli flakes and a couple of pinches of salt, cook for 5 minutes stirring constantyl to prevent the sauce for catching.
Add the vodka, carefully light it up with the burner or a lighter, scraping the base of the pan, then add the tinned tomatoes and bring to a boil. Reduce heat to low and simmer for 15 minutes or until reduced. Pour in the cream, stir to combine, then dimmer for a further 2 minutes. Remove from the heat, allow to cool a little before blending with a stick blender until smooth.
Meanwhile, preheat the oven to 240°C (220°C fan-forced). Cook the pasta in a large saucepan of boiling salted water for half the cooking time of the packet. Drain well, pour into the the saucepan with sauce and stir well to coat.
Tip the pasta and sauce into a baking dish, cover the top liberally with Grana Padano and drizzle with olive oil. Baking for 10-15 minutes or until cooked through and the top is well caramlised. Crack some black pepper over the top, drizzle with a little more olive oil and serve.
