Preheat your oven to 350°F (175°C). This ensures that your cake bakes evenly and rises beautifully.
Grease your Bundt pan thoroughly with butter or cooking spray. This will prevent the cake from sticking and help it release easily once baked.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking soda, salt, ground cinnamon, and cocoa powder until well combined.
In a separate bowl, mix the softened butter, oil, water, buttermilk, eggs, and vanilla extract. Whisk until the mixture is smooth and creamy.
Gradually pour the wet ingredients into the dry ingredients, mixing gently with a spatula until just combined. Be careful not to overmix; a few lumps are perfectly fine.
Gently fold in the mini chocolate chips, ensuring they are evenly distributed throughout the batter.
Pour the batter into the prepared Bundt pan, smoothing the top with a spatula. Bake in the preheated oven for 45-55 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the pan for about 10-15 minutes. Then, carefully invert it onto a cooling rack to cool completely.
While the cake cools, heat the heavy whipping cream in a small saucepan until just simmering. Remove from heat and add the chocolate chips. Stir until smooth and glossy.
Once the cake is completely cool, drizzle the ganache over the top and sprinkle with additional mini chocolate chips, if desired. Slice, serve, and watch it disappear!
