Step 1

Pre-heat oven to 350°F. Lightly grease a bundt cake tin.

Step 2

Add water, 3/4 cup butter, the oil and bittersweet chocolate to a large microwave safe bowl. Microwave 20 seconds at a time, mixing each time with a whisk until smooth. Stir in sugar until blended. Cool 10 minutes.

Step 3

Next, add your eggs to the cooled chocolate mixture one at a time and use a hand mixer to mix into the wet ingredients until well combined.

Step 4

Add flour, cocoa powder, baking soda and salt and mix with whisk just until blended after each addition.

Step 5

Add buttermilk, stirring just until blended. Stir in vanilla. Pour batter into pan.

Step 6

Bake 45 to 50 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes; remove from pan to cooling rack. Cool completely, about 2 hours.

Step 7

In medium microwavable bowl, microwave ganache ingredients on High 45 to 50 seconds, stirring after 30 seconds, until melted and smooth.

Step 8

Cool 10 minutes or until slightly thickened.

Step 9

Place cake on serving plate and drizzle with ganache.

Step 10

Use a spoon to drizzle with marshmallow fluff. If you want to make your marshmallow fluff a little runnier, just add 1 tsp of water and mix into the fluff until well combined.

Step 11

Garnish with curls and mini marshmallows.