Warning: the following theories are untested, unproven, and utterly absurd.
The Cookie-Gravitational Singularity Theory (CGST): This theory proposes that the center of the cookie is actually a miniature black hole, warping the fabric of space-time and causing cookies to be attracted to each other in a vortex of sugary doom.
The Cookie-Induced Time Dilation (CITD) Theory: This theory suggests that the act of consuming a cookie causes time to slow down, allowing the consumer to savor the experience for an eternity.