Preheat oven to 350°F. Butter and line an 8-inch round pan or springform pan with parchment paper (base and sides). If using a springform pan, place it on a sheet pan to catch any leaks.

In a small bowl, whisk together flour, baking powder, cardamom, and salt until well combined.

Using a stand mixer fitted with whisk attachment, or a hand mixer, cream butter and honey for 3 minutes on medium-high speed, scraping down the sides halfway, until smooth and fluffy.

Add eggs and flour mixture by alternating one egg and 1/4 cup of flour mixture at a time, mixing with a rubber spatula after each addition. Continue until all the eggs and flour are used. Stir in milk and orange zest until the batter is almost entirely smooth. Scrape batter into the prepared pan, smooth the surface of the cake, and sprinkle with pistachios. Bake for 45 minutes or until a knife inserted into the center comes out clean. Remove cake from the oven and cool for 30 minutes in the pan.

Meanwhile, prepare the syrup by bringing honey and water to a gentle boil for 5 minutes over medium-low heat, stirring often. Add lemon juice and simmer for an additional 2 minutes. Remove from heat and let cool for 10 minutes.

Using a skewer, poke about 30 holes across the whole surface. Pour 1/4 of the warm honey syrup across the surface. Once it mostly sinks in, repeat this process 3 more times, waiting between pours for syrup to soak in. Then leave the cake to soak for 15 minutes.

Remove the springform pan sides, or serve it directly from the cake pan. Serve warm.