Step 1

Preheat the oven to 325°F and line a cookie sheet with parchment or a silicone baking mat.

Step 2

In large bowl, stir together the butter, brown sugar, and white sugar. The butter should be soft enough to mix thoroughly, but not melted. Add the vanilla, egg, and egg yolk and stir until combined.

Step 3

In another bowl, measure the flour by spooning the flour into the measuring cup and leveling it off. THIS IS IMPORTANT! Add the baking soda and salt and whisk together.

Step 4

Add the flour mixture to the butter mixture and stir to combine. This might take some work, but it will combine.

Step 5

Add the chocolate chips, pecans, and toffee pieces. Mix well. Allow the dough to rest about 5 minutes.

Step 6

Use a 1 1/2 tablespoon cookie scoop to portion the dough out onto the prepared pan placing them about 4 inches apart. Bake for 10 to 12 minutes or until the edges are golden brown. Work in batches to use the remaining dough. Cool on the pan for 5 minutes before moving to a wire rack to cool completely. Store in an airtight container.