Melt chocolate and butter in a bowl over warm water.
Whisk eggs and sugar till creamy. Add in flour with baking powder and then stir in the chocolate mixture.
Stir in the chopped nuts.
Transfer the mixture into a greased lined 20cm square tin and bake in oven Gas 3 / 140° C for 45 minutes. When cooked, leave to cool.
For the sauce; Melt chocolate and butter in a pan and stir in the Ameretto liqueur.
To serve, place a slice of brownie on a warm plate. Spoon over with warm chocolate sauce and decorate with vanilla ice cream and a Physalis.
Please note: this recipe has been created and uploaded by a member of the Tesco Real Food online community. Tesco does not test customer recipes so cannot accept responsibility for the content, validate the results or answer queries regarding them.