Preheat the oven at 180°C.
Lightly crush the cornflakes.
Sieve flour and baking powder together. Add the crushed cornflakes and mix well.
Cream butter and sugar together till it is light and fluffy.
Add the lemon juice and zest and mix well.
Add the flour mixture and mix well.
Allow the dough to chill in the fridge for 15 - 20 minutes.
Take about a tablespoonful of the dough and roll it into a ball. Flatten it slightly between your palms.
Place it on a greased baking tray.
Repeat with the remaining dough. Make sure the cookies are at least an inch apart as they will spread a bit.
Place the cookies in the oven to bake for 12 to 15 minutes or till they are light golden in colour.
Leave the cookies on the baking tray for 5 minutes.
Remove the cookies and cool them on a wire rack.
Store in an airtight container.