01 -
Grab your mixer with the paddle attachment. Beat butter, brown sugar, and white sugar together on medium until it looks fluffy and slightly pale (about 3 minutes).
02 -
Add vanilla and the egg to the fluffy mixture. Keep the speed low while you mix it in, then crank it up to medium-high for a good minute so it all combines well.
03 -
If needed, scrape down the edges of your bowl. Toss in baking soda, salt, and cornstarch and give it about 30 seconds of mixing. Slowly add the flour—go one cup at a time—and mix until it's just blended each time.
04 -
Toss the chopped chocolate into the dough. You can fold it in gently by hand with a spatula or mix briefly on low until it's spread throughout.
05 -
Fire up your oven to 350°F (175°C). Cover a baking sheet with parchment paper.
06 -
Take a serrated knife and carefully slice each croissant horizontally, but don’t go all the way through—leave the back intact so it opens like a book. Arrange them on your baking sheet.
07 -
Spread about 1/2 cup of dough inside each croissant. Press the dough into a thin, even layer, then gently close the croissant back up.
08 -
Grab the leftover dough from each 1/2 cup and put it on the top ends of the croissant. Flatten it a bit between your palms first, then press it onto the croissant’s surface. Do the same for all of them.
09 -
Slide the sheet of crookies into the oven and bake for about 10–12 minutes. The dough should look golden but not overly browned.
10 -
Take the baking sheet out of the oven and let the crookies cool slightly before enjoying them warm.