I haven’t the time to be entertaining on my own today, so let me instead point you to Ben Turpin’s 1909 short feature Mr. Flip. It’s got a lot of what you imagine to see in silent comedies, including what Wikipedia credits as the first filmed pie-in-the-face gag. I certainly accept that it’s an early one, since the pie-in-the-face isn’t framed very well or set up as clearly as it probably would be if the director, “Broncho Billy” Anderson (who played three roles in The Great Train Robbery), or Ben Turpin realized they were producing the first filmed instance of such a slapstick icon. (It’s in the final scene, at about 3:35 into the action.)
Ben Turpin achieved his greatest fame in Mack Sennett comedies and if his face looks familiar it’s probably because, well, it’s a very distinctive face and you probably saw him in clips from the Sennett shorts.
As before, the Archive.org link above is probably going to be a lasting URL, but it’s easier to embed from YouTube so here’s that.