Preheat oven to 350 degrees F.
Line a baking sheet with parchment paper or silicone baking mat. Set aside.
In a medium mixing bowl, whisk together flour, baking soda, pudding mix OR cornstarch and salt. Set aside.
In a large mixing bowl, whisk butter and both sugars until well combined, about 1 minute.
Add vanilla and lemon zest. Whisk in.
Add egg and whisk in well.
Add dry ingredients and 1/2 cup of white chocolate chips and stir in with a spatula or wooden spoon.
Scoop the dough with a regular cookie scoop (1,5 Tablespoon size). Roll into a ball in your hands. Press 5 to 6 chocolate chips on top and sides of the cookie. Place on prepared baking sheet.
Repeat with all. Place cookies 2" apart on baking sheet. I bake 6 cookies on a sheet at a time.
Bake cookies for 10 to 11 minutes. Cool on sheet for 5 minutes, then transfer onto cooling rack.