Lemon joghurt tart with lemon custard

I liked it a lot, because it has quite a bit of dough (and it's also not very unhealthy:)) and the filling is not too sweet with a nice fresh lemon taste.

500 g greek joghurt (still it's better to hang it overnight to drain)
2 eggs
2 lemons (juice and zest)
150 g sugar (you should taste how you like)
* * *
2/3 cups oat flakes
1/3 cups grounded almonds
2/3 cups flour
salt
vanilla
3 tb.s. honey
3 tb.s. water
(put in blender all dry ingredients, then wet and make a dough)

Put the dough in springform about 2-3 mm thick. Blend and whisk joghurt, sugar, lemon juice and zest, then add eggs and whisk again.
Oven 165 C. Place springform with the dough in the oven for about 10 minutes, then take it out, let it cool a little. Then put joghurt filling on top and back to the oven for 45 minutes.
In the meanwhile make custard: 300 ml of milk+ 30 g sugar and vanilla place in a pan on fire, whisk 3 yolks with 30 g four and add this mixture into milk  whisking all the time. Wait for the first bubble and turn the heat off. Now add juice and zest of one lemon.
Put custard evenly on top of joghurt tart and let it cool for several hours. Then you can take it out and enjoy!