Preheat oven to 350 degrees F. Butter an 8 1/2-by-4 1/2-inch loaf pan, line with a strip of parchment paper, leaving an overhang on the long sides to help lift the cake out later (the short sides will be un-lined).: Right away you will sense a warm anticipation as the oven warms, and you can hear the faint hum of the heating element when it clicks on. Preparing the pan with butter and a parchment sling prevents sticking and makes unmolding effortless, which preserves the loaf's crack and crust. If the pan is not well buttered the cake can cling and tear when lifted, so be generous. A common mistake is trimming the parchment too short, which makes removal awkward later.
In a mixing bowl or the bowl of a stand mixer, combine sugar and lemon zest. Rub the zest and sugar between your fingers to release the oils and break up the clumps of zest. Add baking powder and salt and mix to combine.: You will smell a burst of citrus as the oils release into the granulated sugar , the aroma bright and floral, which signals flavor extraction. Mixing in the baking powder and salt at this point ensures they are evenly distributed so the cake rises and tastes balanced. If you skip rubbing the zest, the lemon scent will be muted in the final loaf. Avoid overworking to a paste, you want dispersed oil pockets, not a uniform paste.
Add eggs and beat with the paddle attachment for 3 to 5 minutes or until batter is lightened in color and falls in ribbons from the beater.: As you beat the eggs and sugared zest, notice the color lift and increased volume, the batter becoming pale and airy, which gives a lighter crumb. The ribbon stage is the visual cue that enough air has been incorporated to support rise. Underbeating yields a dense loaf, while overbeating can break down structure, so watch for that ribbon and stop. A common error is rushing this step; patience yields a more delicate texture.
With the mixer running on low, slowly drizzle in olive oil until fully emulsified.: As the extra virgin olive oil is slowly incorporated, you will see a glossy emulsion form, like silk folding into the batter, and a slight fruity scent from the oil blending with lemon. This gentle drizzle prevents the batter from separating, which would cause greasy pockets. If you pour too fast you risk breaking the emulsion and ending up with a dense, oily cake, so take it slow.
Mix in half of flour, followed by half of cream. Scrape down the sides of the bowl as needed. Add remaining flour, and once it is nearly incorporated, add the rest of the cream and lemon juice and mix until just combined (do not overmix, the batter may be a little bit lumpy, that's ok).: Touching the batter you will notice it thicken and then loosen with added heavy cream , creating a tender matrix. Scraping ensures no streaks of flour remain, which would create dry pockets. The lumps are fine and prevent gluten overdevelopment, which keeps the loaf soft. Overmixing is the typical pitfall here and results in a tough crumb, so mix minimally.
Pour batter into prepared baking pan. To help define the crack in the middle of the cake, dip a bench scraper in olive oil and press it in the very center of the batter, about 1/4-inch deep.: As you pour, the batter will settle glossy and smooth, and pressing with an oiled scraper creates a weak line that encourages a clean central crack, giving the loaf its characteristic look. The crack is appealing and helps the syrup pool attractively later. If you skip oiling the scraper the metal can drag and tear the batter, so keep it oiled.
Bake for 50 to 60 minutes or until top is golden brown and a skewer inserted at the highest point near the edge of the crack comes out mostly clean (don't test in the crack itself, which will be a bit softer because of the oil).: During baking the kitchen will fill with lemon steam and the crust will turn a warm golden brown, a reliable visual cue. Testing near the crack avoids misreads since the center will be softer due to oil pooling. Pulling it too soon leads to a gooey center, while baking too long dries the loaf, so aim for mostly clean with a few moist crumbs.
About 10 minutes before the cake is done, prepare the lemon syrup by combining the lemon juice, sugar, olive oil and salt in a small saucepan. Heat over medium, stirring occasionally until sugar is completely dissolved and liquid is clear.: Heating the syrup melts sugar into the Meyer lemon juice , creating a fragrant liquid that will seep into the crumb. You will see the mixture go from cloudy to translucent as sugars dissolve, and a tiny shimmer of oil ties flavors together. If the syrup boils vigorously it can darken or caramelize, so keep it gentle. A common oversight is not dissolving the sugar fully, leaving a grainy finish.
Let cake cool for 5 minutes (just until it's cool enough to handle), then lift out cake using parchment overhang and place on a wire rack set inside a baking sheet to catch overflow. Poke all over the surface of the cake using a thin skewer (I used a cocktail pick which was the perfect length).: The slight cooling period stops the crumb from collapsing, and poking creates channels for syrup absorption. You will hear faint air release as you poke, and the loaf will feel springy. If the cake is too hot it may fall apart when moved, and if too cool it will not absorb syrup well. Avoid poking so much that the structure weakens.
Pour warm syrup over top of cake, focusing mainly on the areas around the crack (if you soak too much syrup in the crack it may get a little soggy). Scrape the overflow from the baking pan back into the saucepan, then pour another coat over the cake.: The sound of syrup hitting warm cake is reassuring, and you will notice the surface darken where it is absorbed, signaling success. Let the first coat sink in before adding more, so the cake soaks evenly. Flooding the crack can cause a soggy center, so direct pours mainly to the top edges. A typical mistake is pouring too fast, causing uneven saturation.
Let cool completely, or, if making ahead of time, wrap the still warm cake in plastic wrap and refrigerate overnight (I personally think it's even better this way).: Cooling allows sugars to redistribute and the crumb to set, and wrapping warm can amplify flavor melding overnight. The texture firms slightly and the cake slices neater after chilling. Leaving it out too long unwrapped can dry the surface, while wrapping immediately once hot can trap condensation, so follow the timing suggested here.
For the glaze, Preheat oven to 350 degrees F. Place cake on an oven-safe wire rack set inside a baking sheet.: A glossy, sweet sheen forms as you brush, and the glaze will settle into fine ridges if it is the right thickness. Brief warming sets the glaze into a delicate crackly shell, which makes the loaf extra pretty. If the glaze is too thin it will run off, and if too thick it will look pasty, so add juice gradually to reach the right viscosity.
Sift powdered sugar into a bowl. Add lemon juice, 1 teaspoon at a time, until glaze is smooth and a nice brushable consistency. Brush glaze over entire surface of cake, top and sides. Like the syrup, try not to fill the crack too full of glaze. Bake for 2 to 3 minutes just to set the glaze (this helps the glaze set up extra crackly).: As the glaze cools you will see it harden slightly and the aroma will intensify, making the cake inviting. Slicing at room temperature yields even slices with a moist interior and a crisp glaze edge. Cutting while too warm can smudge the glaze, while slicing when too cold may make the crumb firmer than desired.
Let cool for 30 minutes or so until glaze is cooled and full set, then slice and serve at room temperature.: Stored properly the loaf retains moisture and flavor, and a quick return to room temperature revives softness. You will notice the scent deepen overnight as flavors meld. Refrigeration keeps it safe longer, but allow slices to sit a bit before serving so the fats soften, enhancing mouthfeel. A common mistake is leaving it unwrapped, which causes drying.
