Preheat the oven to 180C on fan setting. Zest the lemon.
Use electric mixer or hand whip. In a large bowl mix eggs and sugar until combined and smooth. Then add olive oil, flour and baking powder. Mix until combined and then add lemon zest and juice from half a lemon. Mix again.
Pour the mixture into muffin baking tray and bake for 12-20min until golden brown. The baking time depends on how big your muffins tray is. After the 12min check every 2min to see if they turned golden brown.