6cups (6.6 ounces/185 g)crisp rice cereal,such as Whole Foods 365 Brand Organic Brown Rice Crisps
OPTIONAL Topping (see Tips):
2ounces (60 g)milk chocolate,melted, optional
1ounce (30 g)white chocolate,melted, optional
Coat a large silicone spatula with nonstick spray and set aside. Line an 8-inch (20 cm) square pan with plastic wrap and coat with nonstick spray; set aside.
Melt butter in large pot over medium heat. Add marshmallows and melt over low-medium heat, stirring frequently. When marshmallows are about three-quarters of the way melted, add the espresso powder and cinnamon and stir vigorously until marshmallows are completely melted and espresso dissolves. Remove from heat and immediately add cereal to melted marshmallow mixture and use the coated spatula to fold everything together and combine well. Scrape mixture into prepared pan (allow to cool briefly if too hot) and use damp fingers and palms to press down firmly into an even layer. Allow to sit until firm and set, about an hour, or hasten this process by refrigerating briefly (about 15 minutes).
Pull up on plastic wrap and remove the solid square of treats from pan. Set on work surface and peel plastic away. Cut into a 5 by 5 grid into 25 bars. These are amazing if served the same day but they can be stored in airtight container at room temperature for up to 3 days.
If you want to add the optional topping, simply scrape melted milk chocolate into a parchment cone, and do the same with the white chocolate in a separate cone. Snip the end of the milk chocolate filled cone and pipe squiggles all over the bars. Repeat with white chocolate. Refrigerate briefly until chocolate hardens, about 15 minutes, then cut into squares. Best served the same day but may be stored in airtight container at room temperature for up to 3 days.