Cook bacon in a large skillet over medium-high heat until crisp, about 5 minutes. Remove bacon to a paper towel-lined plate; pour off 1 Tbsp. fat; reserve (about 1 Tbsp. will remain). When bacon has cooled, crumble.
Add chickpeas to same skillet and cook, stirring, until lightly browned and slightly crisped, 7 to 10 minutes. Place spinach in a large bowl; scatter chickpeas over spinach.
Remove skillet from heat and whisk in vinegar (watch out, as mixture may spatter). Add mustard and, while skillet is still warm, whisk in reserved bacon fat and olive oil. Quickly scrape dressing into bowl with spinach and chickpeas. Add figs and crumbled bacon. Toss together well, sprinkle with blue cheese, if desired, and serve.