Cream together with an electric hand mixer for 2–3 minutes, or until the mixture is light, fluffy, and pale in color.
Add the egg and egg yolk, and mix again until the mixture is creamy and fully combined.
Mix in the chopped pistachios and chocolate chips until evenly distributed.
Add the flour, cornstarch, and baking soda, and mix just until the dough comes together and no dry flour remains. Do not overmix.
Use a large cookie scoop to portion the dough (about 3 tablespoons each), and place the dough balls on a parchment-lined plate or baking sheet.
Cover and chill for at least 1 hour. I usually chill them overnight for the best texture.
While the dough chills, scoop 18 small dollops of pistachio cream using two teaspoons and place them on a parchment-lined plate. Freeze for 1–2 hours, or until completely solid.
Flatten each chilled dough ball with your fingers, place a frozen dollop of pistachio cream in the center, and wrap the dough around it, sealing completely. Roll into a smooth ball.
Arrange the stuffed cookie dough balls on the prepared baking sheet and bake for 12–15 minutes, or until the edges are lightly golden and the centers look just set. For a gooey middle, slightly underbake them.
Let the cookies cool on the baking sheet for a few minutes, then transfer to a wire rack. Enjoy warm or store for later!
Notes
Line your sheet pan with parchment paper or a silicone mat! This step helps the cookies bake evenly and ensures they release easily from the pan.
Use room-temperature ingredients – Soft butter, eggs, and pistachio cream blend more easily, creating a smoother dough and better texture.
Don’t flatten the cookies. Leave the dough balls tall so they stay thick and soft while baking.
Measure your flour correctly. Too much flour makes cookies dry and puffy. Spoon and level, or use a kitchen scale for accuracy.
Toast the pistachios. Lightly toasting them brings out their natural flavor and adds extra crunch.
Scoop evenly. Use a cookie scoop for uniform cookies that bake evenly and don’t spread unpredictably.
Freeze the pistachio cream completely. The filling must be solid before stuffing; otherwise, it will melt and leak out during baking.
Chill the dough. Chilling for at least an hour helps the cookies hold their shape, prevents overspreading, and improves flavor.
Seal the filling well. Wrap the dough fully around the pistachio cream with no cracks to keep the filling inside.
Don’t overmix the dough. Once the flour is added, mix only until combined to keep the cookies soft and tender.
Use high-quality chocolate. Chocolate chips or chopped bars (55–70%) create the best melty pockets and rich flavor.
Watch your bake time. Slightly underbake for a gooey center and soft texture; the cookies will continue to set as they cool.
Let them cool slightly before moving. They’re delicate right out of the oven, so give them a few minutes before transferring.