Spray the inside of your slow cooker with non-stick cooking spray.

Spread the blueberries evenly across the bottom of the slow cooker and sprinkle with lemon zest and lemon juice.

In a medium bowl, whisk together the almond flour, monk fruit sweetener, baking powder, and salt.

Pour the dry mixture evenly over the blueberries without stirring.

Drizzle the melted butter and vanilla extract over the top of the dry mixture, covering as much surface area as possible.

Cover and cook on high for 2.5 to 3 hours until the edges are golden brown and the center is set.

Let cool for 15 minutes before serving warm.