Preheat the smoker to 275 degrees Fahrenheit.
In a small bowl, mix together smoked paprika, dried rosemary, garlic salt, onion powder, black pepper, and optional cayenne.
Pat the chicken dry with a paper towel.
Rub the chicken with olive oil, making sure to coat evenly.
Apply the mixed spices liberally onto the chicken, both on the skin and inside the cavity.
Place the lemon slices and fresh sprigs of thyme and rosemary inside the chicken cavity.
Lower the chicken onto the half-filled can of beer, so that the chicken is sitting upright with the beer can inserted into its cavity.
Place the chicken in the smoker, using the can and chicken legs to balance it as a tripod.
Smoke the chicken for about 2-3 hours or until it reaches an internal temperature of 165 degrees Fahrenheit, measured at the thickest part.
Once done, carefully remove the chicken from the smoker and allow it to rest for 15 minutes before removing the beer can and slicing.