Preheat the oven to 375 degrees F. Line a baking sheet with a silicone baking mat.
In the bowl of a mixer, cream the butter together with the brown sugar and granulated sugar until it's nice and combined. Add the eggs, peanut butter and vanilla and beat until smooth, scraping the bowl if necessary to make sure everything is incorporated.
In a separate bowl, combine the flour, coffee granules, baking soda and salt. Stir together, then add it to the mixer in 3 increments, mixing on low until it's totally incorporated. Scrape the bowl and beat for a few more seconds. Stir in the chocolate candies, rice cereal and pecans (if using) by hand.
With an ice cream scoop, scoop the dough onto the prepared baking sheet. Refrigerate the scooped cookies for 15 minutes, then bake until golden brown, 9 to 10 minutes. Transfer to a cooling rack and repeat with the remaining dough.