Grease a square springform pan (24 x 24 cm) and dust with flour. Mix flour, sugar, baking soda and ginger. Melt butter in a pot. Add milk and syrup and mix well. Leave to cool.
Stir the eggs into the cooled butter mixture with the whisk of the hand mixer. Stir in the flour mixture. Pour the dough into the springform pan and bake in a preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: see
manufacturer) bake for about 40 minutes. Remove from the oven and let it cool down in the mould.
In the meantime, roughly chop the chocolate. Put the mascarpone in a bowl and melt over a hot water bath. Take it out and let it cool down. Beat the double cream with the whisk of the hand mixer until stiff and fold into the chocolate mixture.
Cut the gingerbread into cubes. Put 1/3 in a glass bowl. Cover with 1/3 cream. Continue to layer until all ingredients are used up. Finish with cream. Wash orange hot, rub dry.
Peel the skin finely with a zest ripper. Decorate trifle with it.