Pipe Blender

As its name suggests, a pastry blender is a tool primarily used for making pies.

It is used to combine cold butter and flour when making dough for pies, cookies, and the like. It allows you to quickly, evenly, and efficiently incorporate cold butter, preventing the dough temperature from rising, which helps in creating flaky pies and cookies.

Beyond pies and cookies, it can also be used for other baked goods such as scones and biscuits.
Additionally, it can be used to make smooth mashed potatoes.