Fill a large pot with water, add a generous pinch of salt, and bring it to a rolling boil. Add the rotini and cook according to the package directions, usually around 7 to 9 minutes, until it turns al dente. Drain the pasta and transfer it into a large bowl to cool slightly.

In a medium bowl or a large measuring cup, combine the honey, apple cider vinegar, 3 tablespoons of the olive oil, lemon juice, brown sugar, smoked paprika, salt, and pepper. Whisk until smooth. Optionally, add a pinch of cayenne for heat.

Heat a large skillet over medium-high heat and add the remaining tablespoon of olive oil. Add the diced chicken in a single layer, seasoning with salt and pepper. Cook for about 5 minutes, flipping occasionally until golden brown.

Pour the dressing into the skillet with the chicken once it looks about 90 percent cooked. Let it bubble and simmer for 3 to 4 minutes, stirring occasionally until the chicken is fully cooked.

Pour the chicken and sauce mixture over the bowl of pasta. Add the spinach and sliced bell peppers. Toss everything together gently until well combined.

Serve warm right after mixing or chill in the refrigerator for later. Store leftovers in an airtight container for up to four days.