Once we've painted over the areas we want to modify, we are going to press Control and 'I' to invert our Mask.

With our mask inverted we're going to click on our Mesh Filter button.

We will also need to enable Smooth Masking by clicking on the Mask option at the top of our 3D Viewport, and choosing Smooth Mask. This will make it so that when we modify our ediges are more natural looking.

All we need to do now is to click and drag our mouse to the right, across our model to slightly grow the arches of our Icing.