Preheat the oven to 350 degrees and grease a small 8-inch round cake pan. In a mixing bowl, cream the butter and sugar until light. Add the egg and vanilla, then stir until combined.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture and mix until a soft dough forms.

Press the dough evenly into the prepared pan. Bake for 18 to 20 minutes until the edges turn lightly golden. Remove from the oven and let the cake cool completely in the pan.

Place the white chocolate chips and heavy cream in a small microwave-safe bowl. Heat in 20-second bursts, stirring between each, until smooth and melted.

Spoon the melted mixture into a piping bag or zip-top bag with one corner snipped off. Pipe simple bone shapes across the cooled cake surface. Let the chocolate set for 10 minutes before slicing.