For the tomato sauce, heat the oil in a large shallow casserole over a low-medium heat. Fry the onion for 5 minutes until starting to soften, then stir in the garlic. Turn the heat up, add the wine and bubble for 2 minutes to reduce a little.
Turn the heat down to a medium heat and add the tinned tomatoes, tomato purée, worcestershire sauce, sugar and most of the basil. Simmer for 20 minutes.
Meanwhile, put the spinach into a colander and pour over a kettle full of just-boiled water, then leave to drain and cool for 5 minutes. Put the spinach into a clean J-cloth or tea towel and squeeze out as much water as possible, then finely chop. Put the mascarpone, garlic and lemon juice and zest into a small bowl, and mix with plenty of seasoning.
When the sauce has simmered, check the seasoning. Heat the oven to 180C/fan 160C/gas 4. Lay the pasta sheets out onto a chopping board, spread 1/6 (about 2 tbsp) of the mascarpone evenly onto each sheet then sprinkle over 1/6 of the spinach, then 1/6 of the ham. Roll up from the short sides of the sheets to make tubes, then slice each into four even pieces. Sit the pasta spirals upright into the sauce, so they fit snugly together. Tuck in the remaining basil leaves and finely grate over the Grana Padano. Bake for 30 minutes until golden and bubbling.