Brown the butter - place the butter in a pot and melt it over medium heat. Let it come to a boil and then cook it for a few minutes, stirring often (especially the bottom of the pot). It will start to bubble a lot and get a nutty aroma. Check the color under the bubbles often, to see if it has brown particles. This will take around 7-10 minutes and you know it's done when there are brown bits at the bottom and the butter has a very nutty aroma. Take a tablespoon of the butter and wait for the foam to disappear to check for browned bits. Be sure to stir often as the browned bits can stick to the bottom and burn. Pour the browned butter with all the bits to a bowl and set aside to slightly cool.
In the mean time prepare all the other ingredients. In a bowl, combine the flour, baking soda and salt.
Roughly chop the pecans, leaving a few whole for topping the cookies and making them even prettier.
Break up the pretzels (leaving some aside for topping the cookies at the end) and combine them with the chopped pecans and two thirds of the chocolate chips (100g). We will use the rest of the chocolate chips for the tops of the cookies.
The browned butter shouldn't be hot anymore by now. If it's still hot place it in the fridge for a bit. Then x it with both sugars for about 2 minutes until well combined.
Add the egg and egg yolk, mix until well combined.
Add the maple syrup and vanilla extract, mix for a few seconds until well combined.
Add the flour mix and briefly mix for a few seconds, then add the pecans, chocolate chips and pretzels, mix until everything is well distributed and combined, but don't over-mix (that develops the gluten in the flour and makes a tough cookie).
Roll some cookie dough between your palms to make a ball or use a big ice cream scoop. I used 60 g (2 oz or two tablespoons) for each cookie, which makes for pretty big cookies. Repeat with all of the cookie dough.
Now use the toppings we set aside (pecans, pretzels, and chocolate chips or pieces of chopped chocolate if you want the chocolate to melt on top) and place them on cookie dough balls.
Place the cookie balls on a tray lined with parchment paper and put it in the fridge for 2 hours (up to 3 days).
When you are ready to bake, preheat the oven to 180°C (350 F) and line a baking tray with parchment paper.
Place the cookie dough balls on the tray at least 5 cm (2 inches) apart. Bake for around 15 minutes. The edges should be golden and cookies may look not done, that's ok. Be sure to not over-bake as the cookies will get too hard and crumbly.