Prepare the Cake Batter:

• Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
• In a medium bowl, whisk together flour, baking powder, and salt.
• In a large bowl, beat butter and sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Stir in orange zest and vanilla extract.
• Gradually add the flour mixture to the butter mixture, alternating with orange juice, beginning and ending with flour. Mix until just combined.

Bake the Cakes:

• Divide the batter evenly between the prepared cake pans.
• Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
• Allow the cakes to cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely.

Make the Cream Frosting:

• In a large bowl, whip the heavy cream with powdered sugar and vanilla extract until stiff peaks form.

Assemble the Cake:

• Place one cake layer on a serving platter. Spread a layer of whipped cream frosting over the top.
• Place the second cake layer on top and cover the entire cake with the remaining whipped cream.
• Decorate the cake with orange slices arranged around the top and sides. Add mint leaves if desired.