Luxurious Dark Chocolate and Hazelnut Tart

OK, so this recipe isn't necessarily of the strictest important... But I made it as a bit of an experiment, and it was unbelievably indulgent. If anyone can suggest any ways to make this recipe suitable for vegans, I would be very happy!

Ingredients

Pastry
160g butter (unsalted)
100g (golden) caster sugar
225 plain flour
50g almonds
1 egg

Chocolate Filling

100g hazelnuts
50g golden caster sugar (or soft brown sugar is preferrable if you have it)
200g dark chocolate
100g butter

1 tbsp amaretto (optional)
1 egg
3 egg yolks








Recipe

1. First of all, make the pastry. Cream together butter and sugar, until mixed well. Then add flour, and ground almonds. Beat the egg, and then add to the mixture. Leave the pastry to cool in the fridge for approximately 30 mins. Once cool, roll out into a pastry tin (23cm diameter). (When I tried this step, the pastry completely fell apart.. Don't worry if this happens for you, just press all the scrap pieces of pastry in the tin at an even level). Then chill again for 15 mins.
2. Heat the oven to 200C/180C fan. Take the pastry out of the fridge, line with baking paper, and fill with baking beans (or dried beans or lentils or anything to weigh it down), then bake for 10 mins. Remove the beans, and cook for another 10-15 mins, or until the casing is golden.
3. Whilst you wait, toast the nuts in a pan (without oil) for a few mins. Turn to a low heat, and add 3 tbsp of sugar and caramelise the nuts gently for a few mins. Take off the heat and leave to cool. Once cooled, roughly chop.
4. Meanwhile, melt chocolate and butter in a heat-proof dish over a pan of simmering water. Once melted together, add the amaretto (if using), and put on the side to cool. In a separate bowl, add the eggs, yolks and leftover sugar, and beat together well. Fold this into the cooled chocolate mix.
5. Once the tart case is cooked, take out of the oven, and turn down the heat to 160C/140C fan. Distribute most of the chopped hazelnuts along the bottom of the case, then add the chocolate mix until level. Cook the tart for 15-20 mins until the chocolate has almost set. Once cooled, scatter the remaining nuts on top for decoration.