Add the flour, xanthan gum and sugar to a large mixing bowl and stir to mix together. Next add the cubed butter and use your fingers and thumbs to 'rub' the mix together until it forms a breadcrumb-like consistency.

Crack the egg into a mug and add the cold water. Whisk lightly to combine and then pour into your mixing bowl. Use a fork to 'mush' the mixture together until it starts to form together into a sticky dough.

Use your hands to bring the dough together into a smooth ball. Wrap in clingfilm and refrigerate for at least 30 minutes - do NOT skip this step!

While your pastry is chilling you can make the frangipane. Add all the ingredients (except the jam) to a large mixing bowl and beat with an electric whisk until fully combined into a thick batter.

Pre-heat the oven to 180'C / Fan 160'C / Gas 4. Remove the pastry from the fridge. Flatten the ball of pastry between your hands a little and then place between two sheets of clingfilm. Roll to around 5mm thick.

Using a pastry cutter, cut 12 circles from the pastry and place them into a 12-hole muffin tin. You can easily re-roll the pastry if needed to get enough circles.

Prick the bottom of each case with a fork - this will stop it 'bubbling' up during baking. Spread half a teaspoon of jam on the bottom of each pastry case.

Fill each case around two-thirds full with the frangipane mix - around 1.5 tsp per Bakewell. Place in the oven and bake for 20-22 minutes until the frangipane is well-risen and golden on top. A skewer in the centre should come out clean.

Remove from the oven and cool completely on a cooling rack before removing from the tin.

Once the Bakewell tarts have cooled, it's time to decorate! Mix the icing sugar and cold water until it forms a thick, white paste. Smooth the icing on top of the Bakewell tarts, top with a glacé cherry and leave to set for 10-15 minutes before eating.