1. Preheat the oven to 200°C (or 180°C for convection). Prepare a baking sheet with parchment paper.
2. In a medium bowl, mix the dry ingredients:
Flour, baking powder, baking soda, cornstarch, and salt.
3. In a large bowl, use an electric mixer to cream together:
softened butter, brown sugar, and white sugar.
➤ Beat until light and fluffy.
4. Add the eggs one at a time, then the vanilla extract.
➤ Continue beating for 3-4 minutes, until the batter is pale and well combined.
5. Gradually fold the flour mixture into the wet ingredients.
➤ Mix just enough to combine, without overworking the dough.
6. Add the chocolate chips and nuts.
7. Form large dough balls (generous tablespoon size). Place them on the baking sheet, leaving about 10 cm of space between each cookie.
➤ Optionally, top with more chocolate chips and nuts.
8. Bake for 13 to 16 minutes, until the edges are golden but the center is still soft.
9. Let cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.