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Given a sandwich in which bread, ham, and cheese (three finite volumes) are mixed up, in any way at all, there is always a flat slice of a knife (a plane) that bisects each of the ham, bread, and cheese.

In other words, however messed up the sandwich-even if it's been in a blender?you can always slice through it in such a way that the two halves have exactly equal amounts, by volume, of the three ingredients.

This theorem generalizes to higher-dimensional ham sandwiches, when it essentially becomes the Borsuk-Ulam theorem: in n-dimensional space in which there are n globs of positive volume, there is always a hyperplane that cuts all the globs exactly in half.

The link Kapagama gives the correct answer!

Pancake theorem is a two-dimensional version of the Ham Sandwich Theorem.

Here is a more easier answer to understand from algebra.com

The Ham Sanwich Theorem
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The Ham sandwich theorem, also known as the Stone-Tukey theorem in topology in mathematics, states that given n objects in n-dimensional space, it is possible to divide each one in half with a single
(n- 1)-dimensional hyperplane.

Why the name Ham Sandwich Theorem?

It takes its name from the case when n=3 and the three objects of any shape are a chunk of ham and two chunks of bread ? notionally a sandwich ? which can then each be bisected with a single cut (i.e. a plane).

Pancake Theorem
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In two dimensions, it is known as the pancake theorem of having to cut two infinitesimally thin pancakes on a plate each in half with a single cut (i.e. a straight line).

Hehehe... you are every perceptive TheSaadia, but I was looking how theorems are related to each other mathematically.