In a medium sized saucepan add the butter and brown it over medium/high heat, takes about 8-10 minutes.
180 g butter
Pour the browned butter into a bowl, and make sure to scrape out all of the brown bits from the saucepan, as that’s all the nutty flavor. Add the instant espresso powder and stir it together. Let it cool down till room temperature.
1 tablespoon instant espresso powder
Once the butter is room temperature add the brown sugar and granulated sugar and stir it together for about 1 minute.
50 g granulated sugar, 150 g brown sugar
Add the egg and vanilla and mix it in.
1 large egg, 1 teaspoon vanilla extract
Add flour, baking powder, baking soda, and salt and fold it together until just combined.
220 g all-purpose flour, ½ teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon salt
Chop the semi-sweet chocolate and add ¾ of the chocolate, saving the rest for the top of the cookies, and fold it into the batter.
100 g chopped semi-sweet chocolate or chocolate chips
Using a 2 tbsp/ 1.3 ounce cookie scoop, scoop out 14 cookie dough balls. Top each cookie dough ball with the remaining chocolate. Place them pre scooped cookie dough in the fridge and let them sit in the fridge for 30 minutes or more.
While the cookies rest, preheat the oven to 180ºC/ 355ºF conventional oven. Prepare and baking sheet with parchment paper.
Once the 30 minutes has passed, add 6 cookie dough to a baking tray lined with parchment paper and bake them for 10-12 minutes.
Let them cool down on the baking tray for 5 minutes as they still will be soft when they are done. After they have cooled down a bit, use a spatula to lift them onto a cooling rack. To finish them off, sprinkle them with flaky sea salt.