Preheat the oven to 350° F (175° C).
Grease a pie plate or round cake pan.
Combine egg, honey, peanut butter, oil, and vanilla in a large bowl; blend well.
Stir in carrots and apple until well-combined.
Sift flour and baking soda and fold into mixture.
Spoon cake batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted in the center comes out clean, approx 30-35 minutes.
Let cake cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.
Top with whipped cream and a doggie treat!
