1. Heat Treat the Flour (Safety First): Place the gluten-free flour in a microwave-safe bowl. Microwave on high for 60 seconds, stirring every 15 seconds, until the temperature reaches 160°F (71°C). This kills any bacteria in the raw flour. Let it cool completely before using.

2. Line a baking sheet or a 9×9 inch square pan with parchment paper.

3. Make the Dough: In a large bowl, beat the softened butter, brown sugar, and granulated sugar together until creamy and combined (about 2 minutes).

4. Add the milk and vanilla extract. Mix until smooth.

5. Add the cooled, heat-treated flour and salt. Mix on low speed until a dough forms. (If it’s too crumbly, add another teaspoon of milk).

6. Fold in the mini chocolate chips.

7. Press the Dough: Transfer the dough to the prepared baking sheet. Use your hands or a spatula to press it into a rectangular slab about ½-inch thick. (It doesn’t have to be perfect).

8. Melt the Topping: In a microwave-safe bowl, combine the 1 ½ cups chocolate chips and coconut oil. Microwave in 30-second intervals, stirring in between, until completely melted and glossy.

9. Pour the melted chocolate over the cookie dough slab. Use a spatula to spread it to the edges, covering the dough completely.

10. Chill: Place the pan in the freezer for 20 minutes (or the fridge for 1 hour) until the chocolate is firm and set.

11. Serve: Remove from the pan. Use a sharp knife to cut it into squares, or use your hands to break it into uneven ‘bark’ pieces. Sprinkle with flaky sea salt if desired.