Preheat oven to 350°F. In a medium bowl, whisk together flour, cinnamon, baking powder, salt, and baking soda.
In a large bowl, combine butter, brown sugar, and eggs. Whisk until smooth. Gradually whisk in dry ingredients just until combined (do not overmix). Using a rubber spatula, fold in apples.
Spoon batter into a 12-cup nonstick Bundt pan, and smooth top (or if you are using mini bundts, there should be enough batter to make 12 mini bundts). Bake until a tester inserted in cake comes out clean, 50 to 60 minutes (about 15-20 minutes for mini bundts). Cool in pan on rack 15 minutes; invert onto rack to cool completely.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.