Tap the big cupcake to bake cupcakes. Spend them in the shop on helpers (ovens, bakers, bakeries and more) that bake automatically every second, and on upgrades that make taps and helpers more powerful.
Each helper costs a bit more every time you buy one. Your progress is saved in this browser, and your helpers even keep baking (at half speed) while you are away for up to 8 hours.