Once you are comfortable with making this cake, it is the gateway to a host of rather impressive desserts that use this simple batter as a foundation. It is so easy to dress up for any occasion by adding fruits and berries to the batter or adding a topping, or even just baking it in a different pan. Since it uses so few ingredients, make sure they are the best quality you can find. Using a vanilla bean rather than extract, for example, does make a difference here.
Preheat the oven to 350°F (180°C). Lightly butter a 9x5-inch (23x12-cm) loaf pan. Line the bottom with parchment paper.
Whisk the 1 3/4 cups (245g) flour, the baking powder, and the sea salt in a medium bowl. Put the butter and sugar in another medium bowl. Use the tip of a small knife to split the vanilla bean lengthwise then scrape the seeds into the bowl, saving the pod for another use. Beat the mixture with an electric mixer on high speed until it is pale, 4 to 5 minutes. (Don't shortchange this step. Because of the high proportion of sugar to butter, this will take some time to change color and texture.)
Beat in the eggs, one at a time, beating well after each addition until light and fluffy. With the mixer on low speed, add the flour mixture in thirds, alternating with two additions of the cream, and beat, scraping down the sides of the bowl as needed, just until smooth.
Spread the batter evenly in the prepared pan and sprinkle the top with the flaky sea salt.
Bake until a wooden toothpick inserted in the center of the cake comes out clean and the top has a nice golden color, 50 minutes to 1 hour.
Let the cake cool in the pan on a wire rack for 10 minutes. Invert the cake onto the rack, remove the paper, and turn the cake right side up to cool completely.