Combine the wet ingredients. Add the brown rice syrup, coconut sugar, peanut butter, vanilla extract, and caramel extract if using, to a saucepan. Heat them over medium heat, stirring regularly, until the coconut sugar is almost melted. This should take 3-4 minutes. Transfer the brown rice syrup mixture to a food processor.
Process the dates. Add the dates to the food processor and process for 15-20 seconds, scraping down the sides as needed, until the dates are fully combined with the syrup.
Process the oats and nuts. Add the rolled oats, oat flour, and macadamia nuts. Process for 7-10 seconds, or until the nuts are roughly chopped (about ¼-inch (0.5 cm). The mixture will be very sticky. This is normal.
Add the rice crisps. Transfer the sticky mixture to a mixing bowl and add the rice crisps. Use your hands to incorporate the rice crisps evenly into the mixture.
Shape into bars. Divide the mixture into 6 pieces (of about 2 ounces / 56g) and shape each into a wide bar. Arrange the bars on a baking sheet lined with parchment paper and let them dry for about 2 hours at room temperature or 1 hour in the fridge.
Drizzle with chocolate. Melt the white chocolate over a double boiler. Once melted, use a spoon (or a squeeze bottle) to drizzle each bar. Transfer to the refrigerator for one hour or until the chocolate is set.
