Line the bottom and sides of a 5-quart or 6-quart oval or round slow cooker with parchment paper, and spray with cooking spray.
In a large bowl, combine the Cake ingredients until smooth. Transfer to the slow cooker. Place a clean dish towel between the slow cooker and the lid, this is to avoid condensation dripping onto the cake.
Cook on High heat for 1 hour.
In a medium bowl, stir Topping ingredients until crumbly. Sprinkle on top of the cake.
Replace the towel and cook on High heat setting for another 30 minutes to 1 hour or until toothpick inserted into the center comes out clean.
Once done, transfer the ceramic insert from the slow cooker to a cooling rack. Let stand for 10 minutes.
Use the parchment paper, to gently lift the cake, and transfer it to the cooling rack to completely cool.
Once the cake has cooled, combine the Glaze ingredients in a small bowl until smooth. Drizzle over the cake.