Cream the room temperature butter with brown sugar and white sugar until well combined.

Add the egg, vanilla extract, and salt, then mix thoroughly.

Sift together rye flour, all-purpose flour, and baking soda, then add to the wet mixture.

Mix gently until no dry flour is visible.

Fold in the dark chocolate and chocolate chips.

Cover the dough with plastic wrap and refrigerate for 30 minutes to 1 hour.

Place dough balls on a parchment-lined baking sheet, leaving space between each.

Bake at 170°C for 12-15 minutes, adjusting for your oven.

Transfer cookies to a cooling rack and let them cool completely.