Preheat oven to 325 degrees.
Using an electric mixer on low, mix brown sugar, butter, and white sugar. After the mixture is blended, add vanilla extract, egg, and egg yolk and mix until creamy.
Mix together flour, baking soda, salt, and matcha.
Lightly chop popcorn into smaller pieces.
Add flour mixture into the batter mix until just blended. Add in white chocolate and popcorn.
Grab a baking sheet, top with foil or parchment paper. Add cookie dough to the sheet, about 1 large tbsp each, and leave at least 2 inches of room between each cookie.
Bake 10 minutes.