1. Make the base

    Preheat the oven to gas 6, 200°C, fan 180°C. In a large mixing bowl, mix 250g crushed digestive biscuits with 125g melted butter.

  2. Press the crumbs into the tin

    Put the biscuit mixture into a 23cm loose bottomed tart tin. Press into the base and up the sides of the tin. Bake in the oven for 15 minutes.

  3. Zest and juice the limes

    Meanwhile, zest 4 limes into a small bowl. Roll each zested lime on a flat surface to help release as much juice as possible, then cut each one in half and juice, adding the juice to the bowl with the zest.

  4. Make the filling

    Put 1 x 397g tin condensed milk into a bowl and add 4 large egg yolks (don’t throw away the egg whites – you can use them to make cute rainbow meringues). Using an electric whisk, beat together for 1 minute. Add the lime zest and juice and beat for a further minute.

  5. Cook the filling

    Pour into the cooked tart tin and return to the oven for a further 15 minutes. Remove and leave to cool. Once it has cooled, chill in the fridge to set completely. This should only take 20 minutes but you can leave it overnight.

  6. Finish the pie

    In a bowl, whip 200ml double cream with 2 tbsp icing sugar to soft peaks. Dollop the cream over the key lime pie. Sprinkle over a little more lime zest to serve.

    Key Lime PiefinalCalories 488 (24%), sugar 29.6g (33%), fat 33.3g (48%), saturates 18.1g (91%), salt 0.52g (9%), based on 10 servings. 

  7. Ingredients

    We've made a handy shopping list so you can get everything you need to make this perfect key lime pie. Don't forget to screenshot before you go shopping!

    250g crushed digestive biscuits
    125g melted butter
    4 limes
    1 x 397g tin condensed milk
    4 egg yolks
    200ml double cream
    2 tbsp icing sugar