This makes one generous portion for a birthday or a reasonable dessert for two. If you prefer, you can easily omit the rosemary, and the olive oil can also be swapped out for the same amount of a neutral vegetable oil. For a vegan and dairy-free option, use almond milk and soy yogurt in the cake, almond milk or coconut milk in the ganache, and serve with vegan ice cream of your choice.
Measuring flour by tablespoons can be a bit finicky weight-wise. When scooping by tablespoons instead of scooping into a cup and leveling, 6 tablespoons can add up to 1/2 cup of flour by weight (63 g) fairly easily, and will result in a denser cake, more like pound cake in texture, that stays pale even when fully baked. The amount above (55g) should be golden brown on top once baked, and is light and more delicate. Happily, both are delicious, just in different ways.
For the ice cream, I ended up adding half the candy cane into the sweetened condensed milk before folding in the whipped cream by accident, but after a second test, I thought that that infused the ice cream with a stronger candy cane flavor and kind of preferred it. (Plus, it turns the ice cream such a pretty pink!) I also used the full 2 teaspoons of peppermint extract for a stronger mint flavor.