Heat the oven to 350 degrees. While the oven's heating, slice the baguette in half lengthwise. Divide the butter, and spread out evenly over each inside half of the baguette. Place the baguette on a baking pan, cut sides up, and bake for 5-7 minutes, or just until lightly toasted.
When the bread's cooled slightly, spread both sides generously with your favorite Caesar dressing. Don't skimp- you don't want it to all squeeze out, but you'll want the flavor and the moisture.
On the bottom half of the bread, layer a bed of spinach leaves. Top that with the drained tomatoes. Sprinkle on Parmesan cheese. Add the bacon slices, then the chicken, and salt & pepper, to taste. Top with another layer of spinach leaves, then the top baguette half. Slice, and serve immediately, or seal and refrigerate, up to 12 hours before serving.