In a mixing bowl, cream together the butter and the sugar until light and fluffy. If using a stand mixer, use the paddle attachment. Add and mix in the lemon juice, almond extract, lemon extract and vanilla extract then mix in the salt and flour. Continue to mix until a dough forms.
Lightly flour a clean surface, remove the dough from the bowl and place it on the surface. Shape the dough into a flat disk and wrap in clingfilm. Place in the fridge for 1 hour.
After 1 hour, preheat the oven to gas mark 4/350°F/180°C/160oC fan and line a baking tray with parchment paper. Lightly flour a surface and roll the dough out to just under ½ cm thick. Using a round cutter, cut out as many circles as possible and place them on the baking tray, leaving a gap between each biscuit. Place in the oven and bake for 13 minutes.
While the biscuits are baking, bring together any scraps and refrigerate for 30 minutes before re rolling. Repeat the process of cutting the circles and baking. Allow the biscuits to cool on the baking tray for 10 minutes then transfer them to a cooling rack to completely cool.
Make the lemon icing by combining the icing sugar and lemon juice. Once the biscuits cool, drizzle the icing onto the biscuits while the biscuits are still on the cooling rack. Allow the icing to set then enjoy.