Flammkuchen is originally from the border region Alsace (tarte flambée), which changed hands between France and Germany enough that the cuisine spread across the border. In Germany you can pretty much find it on menus all over (especially at restaurants specializing in Southern German cuisine), but more traditionally so along the Rhine and closer to France.
I tried the recipe in Luisa Weiss's book My Berlin Kitchen and it turned out well. Her dough uses a small bit of yeast, one of the recipes I've seen uses a flour/salt/oil/water dough, from chefkoch.de. (I also tried making it for Jessica once and for whatever reason it totally failed...the creme fraiche melted like butter and it was a mess...who knows...)
The trick is to roll the dough out really thin, and turn the oven up as high as it goes and bake it quickly. Another tip: use partially frozen bacon, and slice it thin from the package, so you get little piles of thin bacon strips. The Germans often sell Speck in little pre-cut cubes. You want lean bacon, which is closest to German Speck.

