There are three main types of stroopwafels.
Igneous, the most common, are formed by melting a sticky filling and pouring it between two waffles.
Sedimentary stroopwafels are commonly encountered at the bottom of a large container of igneous stroopwafels.
The rarest form is the metamorphic stroopwafel, formed by subjecting igneous and/or sedimentary stroopwafels to extremes of heat and pressure until they fuse together.