For The White Texas Sheet Cake

• First, make the sheet cake. Position a rack in the center of the oven and preheat the oven to 350°F. Lightly spray a 9 x 13-inch sheet pan with cooking spray.
• Mix the dry ingredients. In a small bowl, whisk together the flour, sugar, baking powder, and salt.
• Melt the butter, then add the water and dry ingredients. In a medium, heavy-bottomed saucepan, melt the butter over medium-low heat. Once the butter has melted, add the water and mix together with a heatproof rubber spatula to combine. Bring to a boil over medium-high heat and boil for 30 seconds.

  Remove from the heat and place on a wire rack. Immediately add the dry ingredients and mix until smooth. Allow to cool slightly while you prep the rest of the ingredients.
• Whisk the egg, sour cream, almond extract, and baking soda, then add to the saucepan with the rest of the ingredients. In a small bowl, whisk together the egg, sour cream, and almond extract until combined. Whisk in the baking soda, then immediately add the entire mixture to the mixture in the saucepan and mix until just combined.
• Assemble the cake for baking. Pour the batter into the prepared pan. Pick up the pan and tilt it from side to side to spread the batter into a thin, even layer across the pan.
• Bake the cake. Bake for 18 to 20 minutes, or until the top of the cake bounces back when gently pressed and a skewer inserted into the center of the cake comes out with a few crumbs attached. 
• Meanwhile, toast the almonds for the frosting. Spread the almonds in a single layer across a medium frying pan. Cook over medium heat for 5 to 10 minutes, using a heatproof rubber spatula to toss the nuts every 2 to 3 minutes, until fragrant and brown. Once toasted, scrape the nuts onto a plate fo prevent them from cooking further.
• Make the frosting. In another medium, heavy-bottomed saucepan, melt the butter for the frosting over medium-low heat. Once the butter has melted, add the confectioners' sugar, milk, and salt.

  Continue to cook over very low heat, whisking continuously, until no lumps from the confectioners' sugar remain and the frosting is very smooth, about 5 minutes. At this point, the cake should be done baking.
• Assemble the cake. Place the warm cake on a wire rack for assembly.

  Add the almond extract to the frosting and mix to combine, then, add the almonds and mix until the almonds are completely coated in the frosting.

  Pour over the warm cake. Immediately pick up the pan (be careful—it will still be hot, so use oven mitts!) and tilt it from side to side to quickly spread the frosting into a thick, even layer across the cake. You may need to use an offset spatula to help spread the frosting.

  Cool the assembled cake on the wire rack for 1 hour, or until the frosting has set and feels solid when gently pressed.
• Serve and store. Serve at room temperature. The Texas sheet cake will keep, covered tightly in plastic wrap, at room temperature for up to 3 days.