Heat oven to 375°F/190°C. Combine flour, baking powder and baking soda in medium bowl; set aside. Combine butter, sugar and brown sugar in a large bowl. Beat at medium speed, scraping bowl often, until creamy. Add eggs and vanilla. Continue beating, scraping bowl often, until well mixed. Reduce speed to low. Gradually beat, adding flour mixture, until well mixed. Stir in chocolate chunks. Drop dough by rounded tablespoonfuls, 2 inches/5 cm apart, onto ungreased cookie sheet. Bake for 12 to 15 minutes or until golden brown. Sprinkle with sea salt while still warm.
Makes 3 1/2 dozen.