A cake tester is a small tool used to check if a cake is fully cooked. It is usually a thin, long stick that is inserted into the cake, and if it comes out clean, it means the cake is done. Full definition
Cook in 350 °F oven for 60 minutes or until cake tester inserted into center of loaf comes out clean. (shop.gfjules.com)
Pour hot water into pan to depth of 1 inch, slide shelf into oven, and bake pudding uncovered about 1 hour until cake tester inserted in center comes out clean. (epicurious.com)
Bake for 30 minutes or until an inserted cake tester comes out clean. (foodnetwork.com)