Brown the butter

• In a pan over medium low heat, add the cubed butter and cook low and slow until melted and bubbling.
• Keep stirring until the butter turns brown and smells nutty.
• Transfer to a heatproof bowl and let cool completely.

Mix the dry ingredients

• In a bowl, whisk together the flour, corn starch, baking soda, baking powder, salt, powdered milk and cinnamon.
• Mix well to combine and set aside.

Make the wet batter

• Once the butter has cooled, add the granulated sugar and brown sugar and mix for 1 to 2 minutes until a smooth paste forms.
• Crack in the egg and add the egg yolk, then mix until well combined and smooth, about 2 to 3 minutes.
• Add the vanilla bean paste and mix, then add half of the oats.

Combine the dough

• Gradually add the dry mixture into the wet batter and mix until just combined.
• Add the remaining oats and the chocolate chips and mix until just combined, without over mixing.

Scoop and chill the dough

• Scoop the dough into balls and place them on a prepared baking sheet.
• Refrigerate the dough balls.

Bake the cookies

• Preheat the oven to 350 F.
• Place the cookies onto the prepared baking sheet and bake until the edges are crispy and golden and the center is chewy and soft.
• Let them cool completely before serving.