Preheat oven to 400 degrees F (200 degrees C). Grease a 9-inch cast-iron skillet with butter.
Melt 0.5 cup unsalted butter in a small saucepan over medium heat until browned and nutty. Remove from heat and stir in 1 tbsp fresh thyme. Let cool slightly.
In a large mixing bowl, whisk together 1 cup yellow cornmeal, 1 cup all-purpose flour, 1 tbsp baking powder, and 1 tsp salt.
In a separate bowl, whisk 1 cup buttermilk, 2 eggs, 0.25 cup honey, and the slightly cooled thyme-infused brown butter.
Pour the wet ingredients into the dry mixture. Stir gently until just combined, being careful not to overmix.
Transfer the batter to the prepared skillet, spreading it evenly. Bake for 20 to 25 minutes until the top is golden and a toothpick inserted into the center comes out clean.
Allow the skillet bread to cool in the pan for 10 minutes before slicing into wedges and serving warm.