Preheat the oven to 375°F and grease your 10x15x1″ sheet cake or jelly roll pan
Bring 1 cup unsalted butter and 1 cup water to a boil in a large saucepan.
Remove from heat and stir in 2 cups all purpose flour, 2 cups granulated sugar, 2 large eggs, ½ cup sour cream, 1 teaspoon almond extract, 1 teaspoon vanilla extract, 1 teaspoon baking soda, and 1 teaspoon salt.
Pour into prepared pan and bake for 22 minutes.
Cool completely.
Frosting
In a saucepan, stir together ⅔ cup granulated sugar and 2 Tablespoons all purpose flour. Add 14 ounce can sweetened condensed milk and stir until mostly combined.
Put pan over medium heat and bring to a low boil, stirring frequently.
Boil for 2-3 minutes, stirring constantly.
Remove from heat and stir in ⅛ teaspoon salt and 1 Tablespoon vanilla extract. Cool completely to room temperature or chill before proceeding.
Beat 1 cup butter and 1 cup shortening until smooth and creamy. Add the cooled sweetened condensed milk mixture and beat on high for 10 minutes.
Spread over cake to form a smooth layer. The mixture should be fluffy and smooth.
Decoration
Drain 16 apricot halves from a can well. Allow to drip dry for several minutes or pat them dry with a paper towel.
Arrange drained apricot halves in rows over frosting.
Sprinkle with 1 Tablespoon poppy seeds.
Refrigerate to set frosting.
Store in refrigerator, but serve at room temperature.