Creme Brûlée Cookies

Warm the milk with vanilla in a saucepan over medium heat until gently steaming, then take it off the heat and set aside ¼ cup separately.
Stir the sugar and cornstarch together in a bowl until evenly blended.
Whisk in the egg yolks until smooth, then gradually stream in the reserved warm milk while whisking continuously.
Place the saucepan back over low heat and slowly whisk the egg mixture into the remaining milk.
Keep whisking steadily over low heat until the mixture thickens into a smooth custard without increasing the heat.
Remove from heat and stir in the butter until fully melted and glossy.
Transfer the pastry cream to a bowl, press plastic wrap directly on the surface, and refrigerate until completely chilled and set.
Cream the softened butter, granulated sugar, brown sugar, vanilla, and salt together in a large bowl until light and fluffy.
Blend in the egg and extra yolk until the mixture looks smooth and cohesive.
Gently mix in the flour and baking soda just until no dry streaks remain.
Portion the dough into equal scoops, roll into balls, and arrange on a parchment-lined baking sheet.
Bake in a 350°F (180°C) oven until the edges turn lightly golden while centers remain soft.
Let the cookies rest on the baking sheet briefly, then transfer to a rack to cool completely.
Pipe a generous swirl of chilled pastry cream onto each cooled cookie.
Sprinkle sugar evenly over the cream and carefully torch until melted and amber in color.