Pipe 10 g of hazelnut praliné into a round mould with a flat bottom and place in the freezer.
Roll the crumble out between two sheets of plastic foil and freeze it.
Cut out with a 7 cm ring.
Fill a round 10 cm mould with a thin layer of Italian buttercream and press the frozen hazelnut praliné into it.
Now half fill the mould and press the hazelnut meringue strip into it.
Completely fill the mould with the buttercream and press a slice of crumble on top.
Freeze.
Heat the glazing at 31°C and mix finely with the hand mixer.
Glaze the pastries.
Pipe a large dollop of whipped coffee ganache on the tartlet.
Warm an ice-cream scoop and press in the middle of the ganache.
Fill the hole with a little hazelnut praliné.