Place Graham Crackers, butter, Almond Butter, salt and vanilla into the Thermomix bowl and blend 20 sec/speed 8. Stir through the cacao nibs with a spatula.
Line a 9cm x 7cm tin or container with baking paper that comes above the edges on one side for easy removal later.
Spread the mixture into the lined container and tap on the bench to level. It doesn't need to be perfect. Refrigerate for at least 2 hours before proceeding with the topping.
Either use a microwave, or an induction cooktop or a double boiler to melt the chocolate and the Almond Butter together, giving it a good stir now and again until fully combined and melted. Pour onto the set slice and spread to make even. Refrigerate until completely set. Cut into pieces and enjoy!