Beat the softened butter with the sugar until frothy, gradually add the eggs. Add the Nutella. Mix flour with baking powder, sieve onto the Nutella and egg mixture and stir. Core and peel the pears, then cut into small pieces and fold into the batter. If the dough is too firm, add a little milk.
Pour the dough into a greased springform pan and bake at 175 ° C for 50-60 minutes. Make a chopstick test.
Melt the couverture in a water bath and cover the cooled cake with it.