In a mixing bowl, combine the dry ingredients: gluten-free all-purpose flour, tapioca starch, xanthan gum, sugar, and instant yeast.

Fold the mashed potatoes into the dry mixture until well combined.

Add milk and eggs to the potato mixture. Use an electric hand mixer with a spiral attachment to blend until the dough is incorporated.

Add the light olive oil and salt, mixing until the dough is fully mixed. The dough will be a bit wet and sticky.

Transfer the dough to a prepared loaf pan, smoothing the top with a wet spatula. Cover with a kitchen towel and let rest for 45 minutes, or until doubled in size.

Preheat the oven to 325°F (163°C). Bake the bread in the center of the oven for 45-50 minutes, or until golden brown.

Allow the loaf to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely for at least 30 minutes before slicing.