Sheet cake
A sheet cake or slab cake is a cake baked in a large, flat, rectangular cake pan. Sheet cakes can be grouped into two broad categories. American sheet cakes are usually 2 inches deep, although they are sometimes 3 inches (8 cm) deep. These single-layer cakes are frequently frosted, with decorations and ornamental frosting along the borders and the flat top surface.
Source: Wikipedia
Recipes

Classic Texas Sheet Cake Recipe - BettyCrocker.com
If you love chocolate, and we mean really truly love, then this classic Texas sheet cake is exactly what your sweet tooth craves. Between the scratch-made cake and the decadent homemade frosting, this dessert is a chocolate lover’s dream come true. Unlike...