Preheat your oven to 350°F (175°C). Prepare an 8x8 inch pan by lightly greasing it or lining it with parchment paper.
In a large mixing bowl, whisk together the gluten-free all-purpose flour blend, protein powder, granulated sweetener, leavening agent, and salt. Ensure these dry components are thoroughly combined.
In a separate bowl, combine the unsweetened almond beverage, cultured dairy product, eggs, flavoring extract, and melted coconut oil. Whisk until smooth.
Gradually add the wet mixture to the dry mixture, stirring until just combined. Be careful not to overmix the batter; a few lumps are acceptable. Gently fold in the decorative sprinkles.
Pour the batter into your prepared pan, spreading it evenly. Place the pan in the preheated oven.
Cook for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.