Designing a molten chocolate effect as shown in chocolate advertisements

Start by apply a white to black to white to black gradient in radial mode.

Duplicate the layer. From filter menu select "Render>>Lens Flare ". Apply settings as shown.

Change the layer mode to "Difference" from the layer palette.

Select and merge both the layers. Duplicate the layer. From filter menu select "Distort>>Plastic Wrap ". Apply settings as shown.