Preheat the oven to 180℃. Put an 8" cake pan on top of a sheet of puff pastry and cut a circle around it, making it bigger than the pan so the puff pastry can line the entire pan.

Carefully line the greased cake pan with the pastry. Don't squeeze too hard when getting it into the corners because it will lose its texture.

Use a fork to punch a few holes into the base of the pastry then spread a thin layer of jam over the base but not the entire pan. Then put in the fridge.

After about an hour of chilling, put the butter and sugar into a mixing bowl, and whisk to cream. Then, add the eggs and whisk some more. Now, add the ground almonds and almond extract and whisk more until fully incorporated. Then, take the pastry out of the fridge and pour the mixture into it.

Put in the oven and bake for about 45 minutes. But check every 15 minutes and place a skewer in to check it is clean. Also, the finished product should be springy to the touch. When it's done, leave to cool.

When it's cooled, dust with icing sugar. Then, carefully lift from the cake pan onto a serving plate. Serve with cream or ice cream if you like, and you're done!