Step 1Preheat the oven to 180°C (350°F).Step 2First, prepare the pan. Butter the bottom and sides of a 22-to-25-cm (9-to-10-inch) round cake pan with the 2 teaspoons butter. Sprinkle with the 2 tablespoons sugar, then shake and tilt and swoosh the pan around to coat. It is fun.Step 3Next up, make the batter. Cream together the butter and sugar. Crack in the eggs one by one and mix until thoroughly combined.Step 4Grate the zest from the entire orange over the bowl. Juice the orange and add 125 ml (1/2 cup) of the juice to the batter. Mix until smooth.Step 5In a small bowl, sift together the flour, baking powder, and salt. Fold the flour mixture into the batter and mix until just combined.Step 6Pour into the prepared pan and bake for 20 to 30 minutes, depending on the size pan you used, until the cake is golden brown and starts to pull away from the sides of the pan.Step 7Let cool on a rack for 10 minutes (no more, or the caramel on the crust will harden and stick to the pan), then flip onto a serving plate.Step 8Let cool completely before serving.