Preheat your oven to 350°F (175°C). Line your baking sheet with parchment paper to ensure your cookies bake evenly and do not stick.
In a large mixing bowl, combine the 1/2 cup unsalted butter, 1.5 cups brown sugar, and 1/4 cup granulated sugar. Using an electric mixer, cream together until the mixture is light and fluffy, about 2-3 minutes.
Add in the 3 large eggs one at a time, mixing well after each addition. Then, stir in the 1 tbsp vanilla extract until combined.
In another bowl, whisk together the 1/2 cup all-purpose flour, 1 tsp baking powder, 3.9 oz instant chocolate pudding mix, and 1/2 tsp salt.
Gradually add the dry ingredients to the wet mixture, mixing until just combined. Be careful not to overmix.
Gently fold in the 1.5 cups bittersweet chocolate chips, 3/4 cups semi-sweet chocolate chips, 8 oz Heath toffee bits, and 1 cup toasted pecans if using.
Using a cookie scoop, portion out the dough onto the prepared baking sheet, leaving plenty of space between each scoop.
Place the baking sheet in the preheated oven and bake for 12-15 minutes, or until the edges are set.
Remove the cookies from the oven and let them cool on the baking sheet for about 5 minutes before transferring them to a cooling rack.
