Cut the butter into chunks and place it in the pan over medium heat (preferably a light colored pan). As it melts, you’ll see it foam and bubble — keep stirring or swirling the pan every few seconds. After 4–6 minutes, you’ll see brown bits (milk solids) forming at the bottom and the butter will smell nutty, like toasted hazelnuts. As soon as it turns golden brown (not dark brown!), remove it from the heat. Pour into a heatproof bowl, making sure to scrape all the brown bits from the bottom — that’s where the flavor is. Stir the browned butter in the pan for about 5 secs and set aside. Let cool for 10 minutes before using in the dough.

In a large mixing bowl, whisk together the cooled browned butter, brown sugar, and granulated sugar until smooth.

Add the egg, egg yolk, and vanilla extract. Whisk until combined and creamy.

In another bowl, whisk together the flour, cornstarch, baking soda, baking powder, and salt.

Gently fold the dry ingredients into the wet mixture using a spatula until just combined. Don’t overmix — this keeps your cookies soft. Make sure to scrap the bottom the bowl fo any hidden flour.

In a separate small bowl, stir together the melted butter, brown sugar, cinnamon, flour, and a pinch of salt.

It should look like a thick paste, not runny. If it’s too loose, add an extra pinch of flour.

Drop small spoonfuls of the cinnamon filling all over the top of the cookie dough — don’t dump it all in one spot. This helps the filling spread more evenly. Using a spatula or wooden spoon, fold the dough just 2–3 times. Think of it like making marble cake batter — you want visible streaks of filling, not a fully blended dough. *Important: If you see a big pocket of filling sink to the bottom of the mixing bowl, scoop up a little plain dough from another spot and gently press it under the filling. This keeps too much sugar-butter mix from sitting on the very bottom of any one cookie (which can turn hard like toffee during baking). Stop folding as soon as you see ribbons of cinnamon running through the dough. Overmixing will make the filling disappear and can cause it to leak more when baking.

Cover the bowl and refrigerate for 30 minutes. This keeps the cookies from spreading too much in the oven.

Preheat your oven to 350°F (175°C).

Line baking sheets with parchment paper.

Scoop the dough into 2-tablespoon balls and place them 2 inches apart. When scooping, position the swirl toward the top of the dough ball and seal the bottom with plain dough (so filling isn’t in direct contact with the pan).

Bake for 9-10 minutes, until the edges are set, golden color and the centers look slightly soft.

Let cool on the baking sheet for 5 minutes before transferring to a wire rack to finish cooling.

Beat or vigoursly whisk cream cheese and butter together until smooth.

Add powdered sugar, vanilla, and a pinch of salt.

Mix in milk, a TBSP at a time, until the glaze is thin enough to drizzle.

Glaze the cookies once cookies are completely cool, with a spoon dollop the glaze over the tops of the cookie and with the back of the spoon gently spread through the top of the cookies.