A classic Guyanese frozen treat made with evaporated milk, lots of nutmeg, cinnamon, and Custard Powder. Custard block, is simply frozen Guyanese vanilla custard and is different than homemade Guyanese ice cream. Although many people call ice cream, frozen custard. Traditionally, custard block is made with milk, sugar, spices and Bird’s Custard Powder. Custard powder is simply cornstarch, annatto powder (for color) and artificial flavoring (to give it the vanilla taste). Simply make a slurry by dissolving the cornstarch in some of your liquid, then add the slurry to your liquid to make a thickened egg free custard.