Preheat your oven at 400°F/205°C and prepare a 12-cavity muffin pan.

Mix flour, grated butter, sugar and salt in a bowl until the butter is all covered with the dry ingredients.

Add the egg, cold water and vinegar and work the dough with your hands just until it comes together.

Open the dough between two parchment paper sheets. Leave in the fridge for about 20 minutes or until it becomes easier to work with (i.e., not soft and sticky).

With the help of a cookie cutter, cut rounds 1 inch/2.5 cm bigger than the cavities in your muffin tin. Line each cavity with the dough, making sure it's well trimmed in the top (to have a nicer finish).

Leave the dough in the fridge while you prepare the filling.

In a saucepan, melt the butter and the brown sugar and cook it until it starts bubbling.

In the meanwhile, mix the eggs, maple syrup, lemon juice, vanilla extract and salt in a medium-sized bowl.

Pour the hot filling over the egg-maple syrup mixture and mix to combine.

Remove your pan from the fridge and arrange the pecans and raisins on the bottom of each cavity.

Pour the filling over the nuts, making sure you fill only ¾ of the way up.

Bake at 400°F/200°C for 10 minutes, then lower the temperature to 380°F/190°C and bake for another 10-15 minutes or until golden around the edges.

Make sure to remove them from the pan while still hot -- the filling may spread out and this will make it impossible to remove them later.