Preheat the oven to 375°F and leave baking sheets ungreased.

Whisk together flour, baking soda, and salt in a bowl and set aside.

Beat butter with granulated and brown sugar until pale and creamy.

Mix in the egg and vanilla until smooth.

Add the dry ingredients and mix just until the dough comes together.

Fold in green food coloring until evenly tinted.

Stir in white chocolate chips.

Scoop rounded tablespoons of dough onto baking sheets, spacing 2 inches apart.

Bake for 9 to 11 minutes until edges are set and bottoms lightly golden.

Press decorations onto warm cookies, then cool briefly on the pan before transferring to a rack.