Preheat your oven to 350°F (175°C) and prepare a 10-inch fluted tube pan by greasing it with shortening and dusting with flour.

In a large mixing bowl, cream together softened unsalted butter and sugar until light and fluffy, about 5-7 minutes.

Add eggs one at a time, mixing well after each addition until the batter is smooth.

Pour in lemon juice, lemon zest, and optional lemon extract, and stir until just combined.

In a separate bowl, whisk together all-purpose flour, baking soda, and salt. Gradually add to the wet mixture alternating with sour cream.

Pour the batter into the prepared pan and shake gently to settle.

Bake for 55-60 minutes until golden brown and a toothpick comes out clean.

Cool in the pan for 10 minutes, then invert onto a wire rack to cool completely.

For the icing, beat together sour cream and butter, gradually adding confectioners' sugar, lemon juice, and zest until smooth.

Drizzle the icing over the cooled cake before serving.