For the Candied Pretzels and Walnuts: Heat a sauté pan over medium heat, and add 1/2 cup walnuts, 1/2 cup pretzels, 1/4 cup granulated sugar, 1 Tbsp butter and a pinch of salt. (Ok, two pinches!) Let the sugar melt and stir regularly for about 4 to 5 minutes. The sugar will caramelize; as you stir, coat the pretzels and walnuts. Remove from heat and spread on a parchment-lined baking sheet. Once cool, break into bite-sized bits.
For the Banana Bread Chocolate Chip Cookies: In the bowl of a stand mixer, add butter and sugars. Beat until light and fluffy, about 5 minutes, scraping down the sides periodically.
Add egg, egg yolk, vanilla and bananas, beating until combined.
In a separate bowl, combine flours, cornstarch, baking soda, baking powder and salt, stirring until just combined. Add to the banana mixture, mixing on low until combined. Fold in chocolate chips.
Divide the dough into 4-oz blobs. No scale? It’s about the size of your fist, or a little less than a 1-cup dry measuring cup. Top with more chocolate chips and the candied walnuts and pretzels, if you're doing THE MOST. Place on a parchment-lined baking sheet and chill in the freezer for at least 1 hour.
Preheat oven to 350 degrees F and bake for 15 to 17 minutes. The cookies will be lightly golden at the edges.