Preheat oven to 350°F. Grease a 9x5 inch loaf pan and line with parchment paper.
Whisk together gluten free flour, baking powder, salt, and baking soda in a large bowl.
In another bowl, beat eggs, buttermilk, and olive oil until well combined and smooth.
Pour wet ingredients into dry ingredients and stir until just combined. Fold in sun-dried tomatoes, basil, mozzarella, and garlic until evenly distributed.
Pour batter into prepared pan and smooth the top. Bake for 45-50 minutes until golden and a toothpick comes out clean.
Cool in pan for 10 minutes, then transfer to a wire rack. Best served slightly warm or toasted with butter.