Key lime pie is a perfect recipe for a lovely dessert to be served during hot summer days. The first recipe for Key lime pie was written in the ’30s and included sweetened condensed milk, since in that periodo it was not easy to obtain it fresh. The reaction that generates between the condensed milk and lime juice gives birth to a sort of “cooking” that thicken the filling, and obviates the use of an oven. Today, however, it is recommended to use it also in this case, to eliminate the risks of bacterial fresh eggs and obtain, at the same time, a perfect consistency. It would be better to use the limes from the Florida Keys where possible, but unfortunately it is very difficult to find them in Italy. I prepare my key lime pie with those that I find here and, to be honest, no one has ever complained.
300g Hob Nobs
150g butter, melted
1 x 397g tin condensed milk
3 medium egg yolks
Finely grated zest and juice of 4 limes
300ml double cream
1 tablespoon icing sugar
Extra lime zest, to decorate
Heat the oven to 160°C/fan 140°C/gas 3. Whizz the biscuits to crumbs in a food processor (or put in a strong plastic bag and bash with a rolling pin). Mix with the melted butter and press into the base and up the sides of a 22cm loose-based tart tin. Bake in the oven for 10 minutes. Remove and cool. Put the egg yolks in a large bowl and whisk for a minute with electric beaters. Add the condensed milk and whisk for 3 minutes then add the zest and juice and whisk again for 3 minutes.
Pour the filling into the cooled base then put back in the oven for 15 minutes. Cool then chill for at least 3 hours or overnight if you like. When you are ready to serve, carefully remove the pie from the tin and put on a serving plate. To decorate, softly whip together the cream and icing sugar. Dollop or pipe the cream onto the top of the key lime pie and finish with extra lime zest.