Preheat oven to 180°C (356°F) with circulating air, or 200°C (392°F) with top and bottom heat.
Cut burger buns in half horizontally. Place both halves cut-side up on a baking sheet. Spread herb butter generously on the bottom half. Sprinkle grated Emmentaler cheese evenly over both halves.
Place camembert pieces on the baking sheet among the bun halves. Bake for 10 minutes until the buns are golden brown and the camembert is warm.
While the buns and camembert bake, cut the chicken fillet into small pieces. Heat a pan over medium-high heat and fry the chicken for 5-7 minutes, stirring occasionally, until golden brown and cooked through (internal temperature 74°C / 165°F).
To assemble each burger, spread a layer of wild cranberries on the bottom bun half. Top with 2 pieces of warm camembert (cut one piece in half if needed for easier placement). Add the cooked chicken, then add a few more cranberries on top if desired.