Spray the slow cooker insert with non-stick cooking spray or line with parchment paper.

In a microwave-safe bowl, melt the chocolate chips and butter together in 30-second intervals, stirring between each, until smooth.

In a separate large bowl, whisk together the eggs, egg yolks, and erythritol until light and slightly thickened, about 2 minutes.

Fold the melted chocolate mixture into the egg mixture, then gently fold in the almond flour, vanilla extract, and salt until just combined.

In a small bowl, lightly mash half of the raspberries with water and stir into the batter, leaving some swirls.

Pour the batter into the prepared slow cooker and scatter the remaining whole raspberries on top.

Cover and cook on high for 2 to 2.5 hours until the edges are set but the center still jiggles slightly.

Turn off the slow cooker and let stand for 10 minutes before serving warm.