Preheat the oven to 350 degrees F. Place the baguette on a wire rack set over a baking sheet. Bake until the bread is just warm and toasted, 8 to 10 minutes.
Meanwhile, place the cream cheese and mayonnaise into a large mixing bowl and stir with a rubber spatula until thoroughly combined. Add the Cheddar cheese. Mix until combined, then stir in the pimentos or bell peppers (add them last so they don't get too beat up). Season to taste with salt and pepper.
Cook's Notes: Okay, so this recipe is pretty simple, right? And now you want to experiment and make it your own... Do you have a certain type of cheese you love? Feel free to substitute another type of cheese in for additional flavor. For example, substitute 2 ounces of blue cheese in for 2 ounces of the sharp white Cheddar cheese.
Feel like adding a little kick to your pimento cheese? Substitute another pepper or flavor in for the 2 ounces of pimentos. For example, I've tried Asian chili garlic sauce, kimchi, banana peppers, jalapenos, or grated horseradish.
To roast a red bell pepper, drizzle it with 1 teaspoon vegetable oil and place on a baking sheet. Bake in a 500 degrees F (260 degrees F) oven until the skin is charred, about 40 minutes, turning it halfway through to ensure even roasting. Remove it from the oven and immediately wrap the entire pepper in plastic wrap. Let it steam for 30 minutes. When it is cool to the touch, remove the skin with the back of a butter knife. Remove the stem, seeds and membrane. And that's all there is to it! It is a little more effort than buying jarred roasted peppers, but worth the work.