Cut the Texas toast into small chunks and set aside.

In a large bowl, whisk together milk, eggs, half of the brown sugar, and vanilla extract.

Place Texas toast pieces in the bowl and press them into the egg mixture. Store mixture in the refrigerator overnight.

In a small bowl, combine flour, the other half of the brown sugar, cinnamon, salt, and butter. Using a pastry cutter, work the butter into the flour mixture until it forms a sandy consistency. Store the butter mixture in the refrigerator overnight, as well.

In the morning, place the bread mixture into the greased bowl of a slow cooker. Discard any egg mixture remaining in the bottom of the bowl. Add blueberries to the slow cooker.

Top the bread and blueberries with the butter mixture.

Cook on low for four to five hours or high for three hours.