Melt the butter in the microwave or in a small saucepan over low-medium heat. Pour the melted butter into a large mixing bowl and let it cool down to room temperature in the fridge.

In a bowl add the granulated sugar and lemon zest. Rub it together to release all of the lemon zest flavor, until it looks like wet sand.

Once the butter has reached room temperature add the lemon granulated sugar and with rubber spatula whisk it together for 1 minute.

Add the egg and vanilla extract and mix it in until combined.

In a separate bowl, stir together flour, baking powder, baking soda, poppy seeds and salt. Add the dry ingredients and with a rubber spatula mix it together until combined.

Using a 2 tbsp cookie scoop, scoop out 11 cookies and place them on a tray lined with baking paper. Roll them between your hands into a ball. Place the prepared cookies in the fridge to set for 30 minutes.

Meanwhile, preheat the oven at 180ºC / 355ºF and prepare a baking sheet with baking paper.

Once the 30 minutes has passed, place 6 cookies on a lined baking sheet and put the remaining 5 back in the fridge until the first batch has finished baking. Bake for 10-11 minutes.

Once baked, let them cool down on the baking tray for 3 minutes then use a spatula to lift them onto a cooling rack and let them cool down completely.

In a medium bowl with an electric mixer or in a stand mixer using the whisk attachment, whip together all of the frosting ingredients until it reaches stiff peaks.

When ready to serve, add the cream to a piping bag and pipe the cheesecake frosting on top of the cookies. Sprinkle with poppy seeds and decorate with lemon zest or lemon slices.