In a saucepan over medium heat add the sugar, water and lemon rind.
Bring to a boil and wait 2 to 3 minutes till the sugar is dissolved.
Remove from heat and let the syrup cool down on a cooling rack.
For the Pastry Cream:
In a big saucepan pour only half of the sugar along with the milk and pure vanilla extract.
Stir the mixture and bring to a boil.
When the first bubbles appear remove the saucepan from heat and let it rest for 15 minutes.
In another bowl, whisk the eggs with the remaining sugar and corn starch and set aside.
Return the saucepan on fire and bring to a boil.
When the mixture starts boiling, pour it on the bowl with the whisked eggs, sugar and cornstarch and give it a good stir.
Immediately, pour the mixture back in the saucepan and start stirring quickly as it thickens.
When the pastry cream thickens and there are little to no lumps add the butter cut in cubes and stir till it is fully incorporated.
Pour the pastry cream in a medium bowl and cover tightly with plastic wrap. Note, that the wrap should directly touch the pastry cream.
Refrigerate for 2 hours.
For the Dough:
Preheat oven to 390F (200C).
Separate 6 large eggs in whites and yolks.
In a mixer with the whisk attachment on, beat the egg whites and salt on high speed until frothy.
While beating, gradually add the powdered sugar in small portions. Beware not to add the sugar at once, otherwise the mixture will not rise. Beat until a stiff meringue is formed.
Now add the egg yolks and vanilla extract. Mix till just incorporated.
Remove the mixing bowl from the stand mixer and add the flour and baking powder using a sieve.
Gently, fold in the flour mixture till is fully incorporated, using a spatula.
Fill a pastry bag halfway with the mixture and set aside.
Line two large baking sheets with parchment paper (see notes) or macaron mats.
Using the pastry bag, fill the circles on the parchment paper.
Bake for 8 to 10minutes or till golden brown around the edges. Switch the baking sheets halfway through baking to ensure all cookies are cooked evenly.
Remove from the oven and let them sit for 5 to 10 minutes before moving to a cooling rack.
For the Chocolate Glaze:
Cut the chocolate bar in pieces and place it in a microwave safe bowl along with the butter and heavy cream.
Microwave in 30 seconds intervals stirring every time till the mixture is smooth. Set aside to cool.
To Assemble the Kokakia:
Pair the kokakia.
Remove the pastry cream from refrigerator, give it a good stir with a spatula till smooth and transfer to a piping bag.
Pick one of the cookies and dip it into the cold syrup from the flat side.
Remove and set it upwards on a baking sheet lined with parchment paper.
Repeat the same step for all cookies.
Fill half of the cookies with pastry cream.
Pick the remaining cookies and dip the tops in the chocolate glaze.
Place them on top of the pastry cream and press gently.
Transfer in the refrigerator for at least 2 hours.
Enjoy!
Notes
Ensure butter and eggs are at room temperature.
Note, that the plastic wrap should directly touch the pastry cream.
It is very important to sift the dry ingredients as they will result in a soft and airy cookie.
If do not have macaron mats, you can draw 2 inch circles with a pencil on the back side of parchment paper to help you pipe the dough.
Chilling the kokakia is mandatory otherwise they will fall apart.
Kokakia can be stored in the refrigerator in an an airtight container for up to 4 days.
The number of kokakia might vary depending on the size you made them.
Have any questions about the recipe or want to ask for substitutions? Contact me and I will be happy to help!