1. Preheat the oven to 400°F (200°C) and position your oven rack in the middle. Prep a 12 cup muffin pan with cupcake liners (if you have a second, prep about 3-5 cups in that one as well). Set aside.
2. In a large mixing bowl, add your granulated sugar, lemon zest, and orange zest. Using your fingers, massage/rub the zests and sugar together for about a minute, until the mixture turns a yellow orange. Then add in your 3 eggs, whisking vigorously until fully combined.
3. Next, add in your vegetable oil & heavy whipping cream and whisk until fully incorporated. Sift in your all-purpose flour, sprinkle in your baking powder, and fold the mixture together with a spatula until just combined and no streaks of flour remain. Then fold in your poppyseeds (see notes for optional rest).
4. Scoop out ~1/3 or 1/4 cup scoops of your cupcake batter into each well (just above 3/4 full). It’ll feel like too much, but trust me. Bake at 400°F (200°C) for 5 minutes, turn the oven down to 375°F (190°C), keeping the cupcakes in the oven, and bake for an additional 16-20 minutes or until a knife inserted in the middle comes out clean.
5. Let cool in the pans for about 10-15 minutes before moving to a separate rack to cool completely and continue baking your next little batch with the rest of your batter (make sure to get the oven back up to 400°F before putting the next batch in).

These are best enjoyed the first day (for maximum fluffiness), but will keep for up to 3 or so days stored at room temperature in an airtight container.