1. Preheat the oven to 325 degrees and line two large cookie sheets with silpats or parchment paper.

2. Add ⅔ cup of the dark chocolate morsels to a microwave safe bowl and microwave at 70% power for 30 seconds. Remove and stir, then continue microwaving at 15 second intervals, stirring after each until morsels are fully melted.

3. In the bowl of a stand mixer, combine butter and brown sugar and beat on medium speed until light and fluffy. Add the egg and vanilla extract and beat until combined.

4. Sift together the flour, brown sugar, baking soda and salt.

5. Add the melted chocolate to the mixer on low speed, mixing until combined, then add the flour mixture. Stir in the remaining chocolate chips by hand.

6. Use an ice cream scoop or ¼ cup scoop to drop rounded spoonfuls onto the prepared baking sheets, 3 inches apart.

7. Bake for 16-18 minutes or until a toothpick inserted in the center comes out clean.

8. Allow to cool on the baking sheet for 5 minutes before transferring to a wire rack to continue cooling.