Gather your ingredients to make assembly as easy as possible. You will also need a large bowl, a whisk, and you will need to grease your slow cooker.

Whisk together the eggs, sour cream, yogurt, vanilla extract, and cinnamon. Once these are well combined, gradually add in the milk and maple syrup. Whisk until everything is well blended.

Take half of the bread and layer it in the bottom of the greased slow cooker.

Spread half of the blueberries on the top of the bread. Then take the cream cheese and egg mixture, and spread half of that on the blueberries.

Repeat the layers of the bread, the blueberries, and the cream cheese and egg mixture. Cover your crockpot and refrigerate it overnight.

Before you want to start cooking in your crockpot, take it out of the refrigerator about 30 minutes before and let it warm up a bit. This will help your dish cook evenly without burning around the edges, and it will also prevent the crockpot insert from cracking due to extreme variations in the temperatures.

Cook, covered, on the low settings for 3-4 hours, or until a knife comes out clean when inserted in the center.

Once the dish is finished cooking, make the syrup. Mix the sugar and cornstarch together in a small saucepan. Stir in water until the mixture is smooth. Then add 1/4 cup fresh blueberries. Bring this to a boil, and then cook, stirring constantly, until the berries pop. Remove this from the heat, and then stir in butter, lemon juice, and the few remaining berries for texture. Serve this warm with the French toast.