Combine yeast and 1 tablespoon brown sugar in the bowl of an electric mixer and slowly pour in warm water while stirring frequently. Allow 10 minutes for the mixture to sit and for the yeast to activate.
Add in the room temperature milk, honey, and warm butter to the yeast mixture and whisk until well combined.
In a large bowl, whisk together the flour, rolled oats, cinnamon, and sea salt and add them to the wet ingredients and mix on low-speed until well combined and everything begins to form into a dough-like consistency, about 2-3 minutes.
Change “Mixer head” to kneading accessory and knead dough for 5-10 minutes on high speed until dough ball becomes smooth and elastic and dough springs back when lightly pressed together with 2 fingers. NOTE: If dough is still too sticky, add 1 tablespoon of flour at a time until texture is achieved!
Lightly grease a large bowl with a small amount of olive oil and place the dough ball in the bowl, tossing it around until coated. Cover with plastic wrap (or a towel) and let sit for 1 hour, allowing the dough to rise and double in size.
Once the dough has risen fully, preheat the oven to 350 degrees Fahrenheit and grease a standard 9-inch round cake pan with oil or butter and line the bottom with parchment paper.
Add a bit of flour to a surface and place the dough onto it, stretching it slightly and tucking the dough into a round like shape to ensure that it fits the pan perfectly.
Then, generously brush melted butter (leaving aside 1 Tbsp) atop dough, ensuring that the top is coated evenly and sprinkle a bit of oats atop. Place a piece of plastic wrap (or towel) over the cake pan with bread dough and let sit for another 20 minutes to rise again.
Once the dough has doubled in size (again) or have gotten significantly larger, bake it for approximately 40-45 minutes or until the edges are brown and the center is fully baked through and come out clean when tested with a toothpick or knife.
Remove the bread from oven and let it cool for 5-10 minutes, lift from pan, slice, and enjoy.