Heat-treat the cake mix: Spread the cake mix on a microwave-safe plate and microwave in 30-second bursts, stirring between each, until it reaches 165°F (about 1–1.5 minutes). Let cool completely.
Whisk the base: Whisk the softened cream cheese until smooth, then whisk in the sugar. Add the milk, heavy cream, vanilla, almond extract, and cooled cake mix. Whisk until completely smooth.
Freeze: Pour into a Ninja Creami pint up to the max fill line. Cover and freeze on a level surface for 24 hours.
Process: Run the LITE ICE CREAM cycle. If crumbly, add 1 tbsp milk and run RE-SPIN until creamy.
Add mix-in: Dig a 1.5-inch hole in the center, add the sprinkles, and run the MIX-IN cycle.
Serve: Scoop and serve, or freeze 15–20 minutes for a firmer texture.