Preheat oven to 375°F (190°C). Grease and flour an 18x13-inch sheet pan. In a large bowl, whisk together flour, sugar, baking soda, and salt.

In a saucepan, bring 1 cup of butter and 1 cup of water to a boil. Pour over the dry ingredients and mix. In a separate bowl, whisk eggs, sour cream, and 1 tsp almond extract. Add to the batter and stir until smooth.

Pour batter into the prepared pan and bake for 18-20 minutes, or until a toothpick comes out clean.

While the cake bakes, prepare the frosting. Melt 1/2 cup of butter with the milk in a saucepan. Remove from heat and whisk in powdered sugar and 1 tsp almond extract until smooth. Stir in nuts if using.

Pour the warm frosting over the hot cake immediately after it comes out of the oven. Spread evenly and let cool completely before serving.