Preheat your oven to 350°F (175°C). Grease a baking pan.
In a mixing bowl, combine the gluten-free flour, sugar, baking powder, baking soda, and salt.
Add the milk, melted butter, vanilla extract, and eggs. Mix until well combined.
Pour the batter into the prepared baking pan.
In a small bowl, mix together the brown sugar, chopped nuts, and cinnamon. Sprinkle this mixture over the batter.
Bake for 30 minutes or until a toothpick inserted into the center comes out clean.
Let the cake cool before serving. Enjoy!