Preheat the oven to 350 degrees F. Coat a 9 x 5-inch loaf pan with nonstick cooking spray and line it with parchment paper.
Blend the cottage cheese, eggs, granulated sugar, avocado oil, and vanilla until completely smooth.
Whisk the flour, baking powder, baking soda, and salt in a large bowl. Fold in the cottage cheese mixture just until the batter is combined.
Stir the brown sugar, cinnamon, and melted butter together until the mixture resembles damp crumbs.
Spread half of the batter in the prepared pan and sprinkle with two-thirds of the cinnamon mixture. Add the remaining batter and finish with the remaining cinnamon mixture, then gently swirl the top layer through the batter.
Bake for 48 to 55 minutes, until the center is set and a tester comes out with a few moist crumbs. Cover loosely with foil if the top becomes dark before the center is ready.
Cool in the pan for 20 minutes, then transfer the bread to a wire rack and cool completely.