Preheat the oven to 375 degrees. Combine the butter, sugars and corn syrup in the bowl of a stand mixer with the paddle attachment. Cream the mixture together on high for 3-4 minutes. Scrape down the sides and add the egg and vanilla. Beat again for another 6-8 minutes.
Reduce the speed of the mixer and the dry ingredients. Add the flour, baking powder, baking soda and salt. Just until the dough is combined, do not over mix this part. Scrape down the sides of the bowl.
On low speed, add in the chocolate, butterscotch, oats and espresso powder. Mix only until combined. About 30-45 seconds.
Add in the chips, pretzels and M&M's and mix again on low for another 30-45 seconds. Just until combined, but not crushed up too much.
Scoop your cookies with a cookie scoop or for large cookies use an ice cream scoop. Portion them onto a sheet tray and refrigerate for an hour or up to one week. Or you can quick freeze the dough for about 20-30 minutes and then bake off. You can also freeze the dough and then package in bags and keep the dough on hand for 3 months in the freezer.
Bake the chilled dough for about 18 minutes,(if large cookies). The cookies will spread, so do not put them too close together. These cookies will get lightly dark on the outside and still be a bit yellow in the center. Add about 1 more minute after you see that. Then remove and cool them on the sheet pans. You can keep them for up to about 5 days in an air tight container or freeze them once baked as well. They will be good baked for up to 1 month. If it is anything like our house, they will only last a day! ENJOY!