Gingerbread slice with lemon glaze

Ingredients

• Gingerbread slice
• 200 gram softened unsalted butter
• 2/3 cup brown sugar
• 1/4 cup molasses
• 1 egg
• finely grated zest of 1 lemon
• 2 cup plain flour
• 3 teaspoon ground ginger
• 1/2 teaspoon baking soda
• 1/2 teaspoon ground cinnamon
• 1/2 teaspoon nutmeg
• 1/2 teaspoon cloves
• 1/2 teaspoon salt
• 1/4 cup milk
• Lemon glaze
• 1 cup icing sugar
• 1 tablespoon lemon juice (plus extra)
• shredded lemon zest, for garnish