Start by preheating your oven to 350 degrees and grabbing a lined baking sheet.
Melt your butter and add it to a mixing bowl with the sugar, egg, lemon zest and lemon juice.
Combine your flour, baking soda, baking powder and then gradually add to the wet mixture mixing well.
Toss your frozen blueberries in 1 tbsp of flour and then add to the mixture and fold in.
Scoop out two tbsp sized balls of dough and roll the dough in the extra sugar you have for coating the cookie. Do not flatten yet! Bake these as a ball of cookie dough for 6 minutes, pull the tray out of the oven and flatten the dough with the bottom of a glass cup, then put it back in the oven to bake for another 6 minutes! Flattening the cookie half way through cooking it prevents it from cracking.
Once baked, let the cookies cool before drizzling with melted white chocolate. Set these in the fridge to set and then enjoy!!