01 -
Preheat the oven to 175°C (350°F). Line a 23x23 cm (9x9 inch) baking pan with parchment paper, leaving a 2-inch overhang on the sides for easy cake removal. Set aside.
02 -
In a large bowl, combine the granulated sugar and lemon zest. Massage the zest into the sugar for 20-30 seconds to release the oils and enhance the flavor.
03 -
Add the butter and oil to the bowl. Using a hand mixer or stand mixer fitted with a paddle attachment, beat on medium speed until light and fluffy (about 2 minutes). Scrape down the sides as needed.
04 -
Mix in the eggs one at a time, ensuring each is fully incorporated before adding the next. Scrape down the sides of the bowl.
05 -
Add the lemon juice and vanilla extract to the mixture. Mix on low speed until just combined. The mixture may appear curdled but will come together when dry ingredients are added.
06 -
In a separate bowl, whisk together the flour, baking powder, baking soda, salt, and poppy seeds.
07 -
Add the dry ingredients to the wet mixture in three additions, alternating with the sour cream and milk, starting and ending with the dry ingredients. Stir gently and avoid overmixing.
08 -
Spread the batter evenly into the prepared pan using an offset spatula, smoothing the top.
09 -
Bake for 30-35 minutes or until the top is golden and a toothpick inserted into the center comes out with a few crumbs. If the cake browns too quickly, lightly cover with aluminum foil towards the end of baking. Do not overbake.
10 -
Allow the cake to cool in the pan for 30-45 minutes. Use the parchment overhang to lift it out onto a wire rack. Cool completely before glazing.
11 -
Whisk together the powdered sugar, milk, or lemon juice, and vanilla extract (if using). Adjust consistency as needed.
12 -
Pour the glaze evenly over the cooled cake, allowing it to drip slightly over the edges. Let it set before slicing.