Process all yellow layer ingredients to combine in a food processor. Transfer this mixture into a lined tupperware container or medium-sized bread loaf pan (I used one that’s 8″ x 4″). Press down into an even layer. Cover with a small piece of parchment paper and press down once again with a flat-bottomed object to make sure that layer is smooth (I like to think of it as “ironing” 🙂 ). Remove the parchment from the top and place the pan in the freezer while working on the next step.
Clean out the food processor (so there’s no discoloration of the white layer). Process all white layer ingredients until smooth. Pour this mixture over the yellow layer in the pan. Allow to sit a minute, then sprinkle and decorate with toppings (if using). Note: if your mixture is too warmed up (very liquid), the poppy seeds might sink in a bit, so if that’s the case best to chill the pan for 15-20 mins first, then sprinkle with the toppings. Freeze for 5 hours or overnight for the bars to set. Trim off uneven edges and slice into bars and enjoy! Keep leftovers frozen.