Preheat your oven to 350°F. Line a 9×13 inch baking pan with parchment paper, leaving some overhang on the sides for easy lifting later.
In a large mixing bowl, whisk together the melted, slightly cooled butter, brown sugar, and granulated sugar until the mixture looks thick and glossy.
Whisk in the eggs one at a time until fully blended. Stir in the vanilla extract. At this point the batter should look smooth and a little silky.
Sprinkle the flour, baking soda, and salt evenly over the wet mixture. Use a spatula or wooden spoon to gently fold the dry ingredients into the wet until just combined.
Fold in the chocolate chips and cherries gently so they are evenly distributed. Keep some aside to sprinkle on top later.
Spread the batter in the pan. Use a spatula or clean hands lightly sprayed with baking spray to press the dough into an even layer that reaches all the corners of your pan.
Bake for about 18-20 minutes, or until the top is mostly set but still kind of jiggly.
Sprinkle the top of your bars with some extra chocolate chips and cherry pieces.
Return the pan in the oven and bake for around 7-15 minutes, until the top of your cookie bars is lightly golden and the center looks just set. The edges should look slightly browned and firm, but the middle should still look soft.
Let the pan cool completely on a wire rack. This helps the bars firm up and also slice cleanly.
Once cool, use the parchment hanging over the sides to carefully lift the slab out of the pan. Cut into 12 to 24 bars, depending on how big you like them. These are delicious at room temperature, but I also love them slightly chilled from the fridge for a fudgier texture.