In a large bowl mix together all the wet ingredients for your cake. Then sift the dry ingredients (don't use the chocolate chips yet) into the wet ingredients with a fine mesh sieve or sifter. Mix the wet and dry ingredients together.
Pour the batter into the slow cooker and spread it out. Sprinkle the chocolate chips on top of the batter. Mix together the chocolate sauce in seperate cup then pour it over the batter. Let the chocolate sauce sit on top of the batter, do not mix it in.
Cover the slow cooker. Cook the cake for 2 to 2 ½ hours on the low setting. The cooking time vary depending on the size of the slow cooker so keep an eye on it. It is done with the top is shiny and looks fudgy. Your cake should not look dry. Scoop the cake out and serve in bowl topped in sweetened whipped cream and berries.