Preheat oven to 350F and line an 8x8 inch baking pan with parchment paper.
Whisk together the gluten free all-purpose flour, granulated sugar, and baking powder. Add the milk, melted butter, eggs, and vanilla extract, mixing until smooth.
Pour the batter into the pan and bake for 25 minutes until a toothpick comes out clean. Let the cake cool, then cut into bite-sized cubes.
Wash and chop the fresh strawberries, toss them with 2 tablespoons of granulated sugar in a bowl, and let them sit for 15 minutes to release their juices.
In a separate cold bowl, whip the heavy whipping cream and powdered sugar until stiff peaks form.
To assemble, grab 4 mason jars. Layer a handful of gluten free cake cubes at the bottom of each jar.
Top with a spoonful of the juicy strawberries, then a layer of whipped cream. Repeat the layers until the jars are full, finishing with whipped cream and a fresh strawberry.