In a blender, add the yogurt, Limoncello, stevia, lemon flavor, vanilla extract, and butter flavor. Blend until smooth.
In a small bowl, whisk together the corn starch, xanthan gum, baking soda, and salt. With the blender running, slowly add in the dry ingredients. Blend until smooth. Feel free to add natural yellow food coloring or ground turmeric for color!
Place the frozen ice cream maker attachment onto the stand mixer and turn on the "stir" speed. Pour ice cream mixture into the ice cream bowl and churn until soft-serve consistency.
Transfer the ice cream into a freezer-safe dish. Cover and freeze until it's the texture you prefer (~3-5 hours). Serve and enjoy!