In a large, straight-sided skillet, heat the olive oil over medium heat and add the bacon. Cook, flipping occasionally, until the bacon is golden and crisp, 6 to 8 minutes. Transfer to a plate lined with paper towels. Add the 3 whole cloves of garlic and the bread to the pan, and sauté until the garlic is tender and golden and the bread is deep golden brown on both sides, 4 to 5 minutes. Using tongs or a slotted spoon, transfer the whole garlic cloves and 4 of the toasts to a mortar (or a small food processor). Set aside the remaining 2 slices of toast on a paper towel.
To the same skillet, add the 3 cloves chopped garlic, the cumin, and the paprika. Cook, stirring, until fragrant and the garlic begins to brown, 15 to 30 seconds. Increase the heat to medium high and immediately begin adding the spinach in batches, stirring to wilt. When all the spinach is in the pan, add the chickpeas, 1 cup water, 1 tsp. salt, and several grinds of black pepper. Bring to a simmer.
Meanwhile, mash the bread slices and garlic in the mortar or process in the processor (don't mash the 2 reserved toast slices) with the vinegar and 1 to 2 Tbs. water until puréed.
Stir the mashed bread mixture into the spinach, lower the heat to medium, and simmer until the liquid has reduced almost completely but the spinach is still moist, about 10 minutes. Crumble the bacon and stir it in. Taste and add more salt or vinegar if needed. Crumble the reserved toast over the spinach. Serve hot or warm.