The expression “sorta speak” seems to be quite common. Some people will “correct” you by saying it should be pronounced and written “sort of speak.”
But neither form is standard. When you use an expression that is not meant entirely literally, or is slang or informal, you may follow it with “so to speak” or “in a manner of speaking.” It is most appropriately used to acknowledge that you have just expressed an idea in an unusual fashion.
Some people use it to label statements that are simply untrue, but that is stretching the expression too far.
Examples of standard usage: “They had money to burn, so to speak.” “He went ballistic, so to speak.” “In my college years I was an academic nomad, so to speak.”
Other similar expressions are “as it were,” “in a manner of speaking,” and “figuratively speaking.”
A much less common but more amusing misspelling than “sorta speak” is “soda speak.”