Crispy Chocolate Rice Cake Bars

In a large bowl, combine the crumbled rice cakes and mix-ins. 2. In a small microwave-safe bowl, combine the nut butter, chocolate chips, brown sugar, and vanilla extract. Microwave on high in 30-second intervals until melted and smooth. 3. Pour the melted chocolate mixture over the rice cake mixture and mix well to combine. 4. Transfer the mixture to an 8×8 freezer-safe dish that’s lined with parchment. Freeze for 30 minutes. 5. In another small microwave-safe bowl, melt the white chocolate chips (if using) in 15-second intervals until melted and smooth. 6. Remove the bars from the freezer and drizzle with the melted white chocolate and sprinkle with sea salt. 7. Transfer back to the freezer for 10 minutes to set. Cut into squares and store at room temperature for up to 3 days, in the refrigerator for up to 7 days, or in the freezer for up to one month.