Start by creaming the butter and sugars. In a large bowl, beat together the melted butter, granulated sugar, and brown sugar until the mixture is light and fluffy.

Incorporate the eggs and vanilla. Add the eggs one at a time, followed by the vanilla extract, mixing well after each addition until the mixture is smooth.

Combine dry ingredients. Gradually mix in the flour, cinnamon powder, cornstarch, baking soda, and baking powder until just combined, taking care not to overmix.

Add the pecans and toffee bits. Fold in the toasted pecans and toffee bits, if using, until they are evenly distributed throughout the dough.

Chill the dough. Refrigerate the dough for 30-45 minutes to firm up, which will make scooping and shaping the cookies easier.

Shape the cookies. Using a spoon or cookie scoop, form small balls of dough. If the dough crumbles, press it gently with your hands to bring it together.

Prepare for baking. Preheat your oven to 350 degrees F and line a cookie tray with parchment paper. Place the dough balls on the tray, leaving space between them for spreading.

Bake to perfection. Bake the cookies for 11-14 minutes or until they are golden brown around the edges. They will puff up in the center and settle as they cool.