Preheat oven to 350° Fahrenheit. Please note we are at a very low altitude, adjust accordingly.
In a small saucepan, melt the butter over medium heat. Bring to a simmer and simmer over medium heat at least 3 minutes stirring often. Set aside in a heat safe bowl to cool slightly - at least 5 minutes. See notes.
In a bowl whisk together flour, oats, cinnamon, baking soda and salt.
In a mixing bowl cream the melted (but cooled) butter, yogurt, brown sugar and sugar with a hand or stand mixer. Mix for about 30 seconds.
Add in molasses and vanilla extract and mix again for about15 seconds until mixed through.
Add both eggs and mix for 30 seconds to 1 minute, until mixed well and a creamy texture. You will not be using the mixer after mixing in the eggs.
Pour the dry ingredients into the wet ingredients and stir with a whisk until incorporated and no large lumps. Small lumps are ok, do not over mix. Batter will be thick.
Using a spatula or a spoon, gently fold the apple chunks into the batter.
If your bundt pan is non stick, scoop the cake batter into the pan and spread evenly - it doesn't pour easily.If your bundt pan is not non stick, lightly grease the inside of the pan. Scoop the batter into the pan and spread evenly.
Place on center rack in the preheated oven and bake for 40-50 minutes. The top will be golden brown, possibly have a couple cracks (it's ok you don't see them when cake is out of pan) and a toothpick should come out clean.
Remove from oven and set on a cooling rack. Allow to cool fully before removing from pan.
Once cake is cooled completely, take a small silicone spatula and gently run it between the cake and the pan to be sure it will come out of the pan easily.
Drizzle the caramel syrup over the cake in the amount you like before serving and enjoy!
Serving sizes are estimated.For the oats - Use either old fashioned or quick cook oats. Do not use steel cut and I don't recommend using instant.For the molasses - I recommend using molasses for the flavor but if you do not have it, you can add 2 packed Tablespoons dark brown sugar on top of the sugar in the mix. You would add the extra brown sugar with the rest of the sugar, not after like the molasses.For the apples - You can use your favorite here. Granny smith is usually a favorite because they are not as sweet, but we use a sweeter apple. The sweeter the apple, the more sweetness added to the cake.Salted caramel - Our recipe makes about a cup but you can use more or less then half a cup. If you make the caramel ahead of time, it needs to be heated back to a liquid to drizzle it.For the butter - Cooking butter for a few minutes brings out a more toasted flavor. The longer you cook it, the more flavor it has. You can cook it for up to 6 min, but I wouldn't cook longer. It will have some separated pieces on the bottom of the pan, you want them in your cake along with the melted butter!The butter needs to cool a little bit before mixing with the yogurt and sugar. I melt the butter before chopping the apples so it has enough time to cool but not become solid again.