Pre-heat the oven to 350ºF.
Line two baking sheets with parchment or silicone.
Beat the butter with a mixer on medium high speed for 1 minute.
Add the brown sugar and the granulated sugar and beat for another 2 minutes.
Add the Eagle Brand® Sweetened Condensed Milk, the egg yolk, and vanilla. Mix everything until combined.
Add the flour, cornstarch, baking powder, baking soda, cream of tartar and salt to the bowl.
Mix at low speed until incorporated. You may have to finish stirring with a spatula.
Scoop the cookie dough and roll between your hands to smooth it out.
Then place the cookie on a tray lined with parchment or silicone.
Press the cookie balls down to flatten them until they are between 1/2” and 3/4” thick.
Bake the cookies in the pre-heated oven for about 8 minutes. The cookies should look golden around the edges, and not feel super soft on top if you touch them gently.
Remove the cookies from the oven and let them come to room temperature.
To make the Pastry Cream, start by placing 1 1/4 cup of milk in a saucepan and heat it up over medium heat just until you see the first bubbles appear.
Using a mixer, whisk the yolks together with the sweetened condensed milk.
Take the remaining 1/4 cup of milk and mix with the cornstarch. Whisk well so the cornstarch will dissolve.
Add the cornstarch/milk mixture to the sweetened condensed milk and yolks. Whisk well.
Once the milk has been heated until the first bubbles begin to appear, remove it from the heat and pour about 1/4 cup of the hot milk in the sweetened condensed milk mixture, while whisking with the mixer.
This process is called tempering the eggs, and we add the milk slowly in order to not make scrambled eggs out of the yolks we have in the bowl.
Slowly continue to add all the milk until it’s been all added.
Pour the whole mixture back in the saucepan through a fine mesh sieve, this will help catch any bits of egg that might have cooked.
Place the pan over medium heat, and stir with a spatula the whole time while you cook the custard.
It should take some time, but slowly you will see the custard begin to thicken at the bottom.
It will seem as the custard is lumpy, but trust the process, keep on stirring and scraping the bottom of the pan, and soon the whole mixture will thicken up. Don’t leave the heat too high, or the custard will indeed become lumpy because some bits of it will burn at the bottom of the pan.
After a few minutes the whole mixture will be thick and creamy, when that happens, remove it from the heat and add the butter.
Stir until the butter has melted entirely and incorporated with the mixture.
Then, add the vanilla and stir.
Cover the bowl a piece of plastic wrap directly on the surface of the custard, to prevent a skin from forming.
Refrigerate the custard for at least 2 hours or up to 3 days or so.
To make the Chocolate Glaze, place the Eagle Brand® Sweetened Condensed Milk, the chocolate and the heavy cream in a small pot and stir over medium heat, until the chocolate has melted entirely. Don’t let the mixture come to a boil.
Remove from the heat and let it cool down to room temperature before drizzling over the cookies. If the glaze becomes too thick, add a bit of heavy cream to it and whisk until it’s at the desired consistency.
You want the glaze to be a bit runny but not too much, it should drip over the pastry cream slowly.
Place the pastry cream in a piping bag fitted with the tip of your choice. I used a 6B.
Pipe some pastry cream on top of the cookies.
Top the pastry cream with a bit of chocolate glaze.
Store in the fridge for up to 5 days.
Recipe by our friend Camila @Piesandtacos