Preheat the oven to 350°F (180°C). Line a baking sheet with parchment paper.
2. Step
In a medium bowl, whisk together the brown sugar, granulated sugar, salt, and butter until fully incorporated.
3. Step
Add the corn syrup, milk, and vanilla. Whisk to combine.
4. Step
Sift the flour and baking soda into the wet ingredients and fold in with a spatula until just incorporated.
5. Step
Fold in the chocolate chunks until just combined.
6. Step
Scoop the dough with an ice-cream scoop onto the prepared baking sheet baking sheet, leaving at least 4 inches (10 centimeters) of space between cookies and 2 inches (5 centimeters) of space from the edges of the pan so that the cookies can spread evenly.
7. Step
Bake until thin and golden brown, with an even color from edge to center, about 16 minutes.
8. Step
Let the cookies cool completely, then dunk in the melted chocolate. Let chocolate set for about 30 minutes.