In a bowl, beat the butter with an electric mixer for 1 minute. Add the sugar and beat for another minute until creamy.

Add the eggs one at a time, mixing well after each addition.

Add the lemon juice, lemon zest, and salt. Mix on low speed until combined. The mixture may look separated and that’s okay.

Pour into a small heavy-bottom saucepan and cook over medium-low heat. Do not let the curd boil at any point, and stir continuously to prevent the eggs from curdling.

Cook until the curd reaches 170°F (76°C), or until thick enough to coat the back of a spoon.

Immediately strain the curd through a fine mesh sieve into a clean bowl to remove the zest and ensure a silky smooth texture.

Cover and refrigerate for at least 2 hours until chilled and thick. Reserve 60 g of curd for the ganache.

Preheat the oven to 350°F (175°C), or 325°F (160°C) for convection.

Grease a 12-cup bundt pan generously with softened butter and dust with flour, making sure to coat all the details and crevices.

Whisk together the flour, salt, baking powder, and baking soda. Set aside.

In a small bowl, rub the lemon zest into the sugar using your fingertips until fragrant.

In a large bowl, beat the butter for about 2 minutes.

Add the lemon sugar and beat until light and fluffy, about another 2 minutes. Add the eggs one at a time.

Mix in the sour cream and lemon juice.

Add half of the dry ingredients and mix briefly, then add the milk.

Add the remaining dry ingredients and mix until just incorporated.

Spread about 2 cups of batter evenly into the prepared bundt pan.

Scatter about ⅓ of the blueberries over the batter. Add another layer of batter.

Scatter another portion of blueberries.

Repeat until all batter and blueberries are used, finishing with batter on top.

Smooth the top.

Bake for 45–65 minutes, until the cake springs back lightly and a toothpick comes out clean. If browning too quickly, loosely tent with foil.

While the cake bakes, combine the lemon juice, sugar, and lemon peel in a small saucepan.

Bring to a brief boil just until the sugar dissolves. Remove from heat and discard the lemon peel.

When the cake comes out of the oven, let it rest for 5 minutes.

Prickle holes all over the surface and slowly pour the warm syrup over the cake.

Cool for another 15 minutes before unmolding. Transfer to a wire rack and cool completely.

Place the white chocolate in a bowl.

Heat the 60g lemon curd and 45g heavy cream together in a separate pan until steaming but not boiling.

Pour over the white chocolate.

Let sit for 1 minute, then whisk until smooth.

Allow the ganache to sit at room temperature for 1–2 hours until it reaches a thicker, pourable consistency.

To speed it up, refrigerate in 5–10 minute intervals, stirring between each interval. Watch closely because once it starts setting, it firms up quickly and can become solid.

Pour or spread over the cooled cake. Decorate with more blueberries and lemon zest.