Amamela tart with jam, apples and amaretti

An unusual recipe circulating online. I tried it and it is delicious. Read on to discover the secret of its bubbles.
INGREDIENTS FOR A 24 CM TIN

SHORTCRUST PASTRY
400 G FLOUR
200 G BUTTER
150 G ICING SUGAR
1 LEMON, GRATED ZEST
4 EGG YOLKS
VANILLA POWDER OR POD
1 PINCH SALT
FILLING
2 GOLDEN DELICIOUS APPLES
150 G APRICOT JAM
AMARETTI AS NEEDED
1 TEASPOON CINNAMON
A LITTLE MILK TO BRUSH
ICING SUGARIn a processor, or mix by hand ) I put flour, sugar, vanilla, butter, yolks, salt and lemon zest.I quickly mix into crumbs.I remove, form a block, wrap and refrigerate for 1 hour.I take 2/3 of the dough.I roll a disc. I line a buttered, floured tin, leaving a couple of centimetres of side, and prick with a fork. A shallow tart tin is easier.I roll remaining dough into a smaller disc.I peel and slice apples half a centimetre thick.I spread jam on the base and add apple slices.I cover with apples and a teaspoon cinnamon.I cover with amaretti.I pack closely without overlapping.I carefully lay pastry disc on top and seal edges.I brush with milk.I bake at 180°C conventional for 50 minutes, covering with foil for the last 10 minutes if too dark.Cool, unmould and dust with icing sugar.Delicious, crisp outside with sweet, creamy filling, a must-try.