Pass the ricotta through a fine sieve into a mixing bowl. Whisk in the mascarpone, icing sugar and the orange zest, set aside. Wash, hull  and slice the strawberries. Meanwhile prepare a syrup, bring to the boil the water and sugar together with the anise, cinnamon, ginger and orange juice, remove from heat and allow cooling. Start dipping the savoiardi biscuits in the warm syrup and place into your serving dish. Cover with strawberry slices and spread with the ricotta cream. Repeat the process for a second layer. Decorate the tiramisu with strawberries and mint springs.