Put butter in a pot and melt it. Finely chop 50 g walnuts. Put the lady fingers in a freezer bag and crush them to fine crumbs with a rolling pin. Mix sponge crumbs, walnuts, sugar and liquid butter well. Spread the bottom of a springform pan (24 cm Ø) thinly with oil. Spread the crumb mixture on the base and press it down to an even base. Chill for about 20 minutes.
Mix the cream cheese and 125 g Dulce de Leche with the whisk of the hand mixer until smooth. First add eggs, then starch. Pour cream onto the crumb base. Bake in the preheated oven, 2nd shelf from below (electric oven: 150 °C/ convection oven: 125 °C/ gas: level 1) for approx. 50 minutes. Turn off the oven, open the door halfway and let the cheesecake cool down. Then let it cool down completely on a cake rack
Spread 125-150 g Dulce de Leche on the cake and chill for 3-4 hours (or overnight). Coarsely chop 25 g walnuts. Remove the cheesecake from the tin, sprinkle with walnuts and cut into pieces
On 16 pieces:
waiting time approx. 4 3/4 hours