Preheat and prep: Heat oven to 350°F (175°C).
Line a 12-cup muffin tin with paper liners.
Mix the dry ingredients: In a bowl, whisk 1 1/2 cups flour, 1 cup sugar, 1 1/2 teaspoons baking powder, and 1/2 teaspoon salt.
Cream the fats: In a large bowl, beat 1/2 cup soft unsalted butter until creamy. Mix in 1/4 cup neutral oil until smooth.
Add eggs and flavor: Beat in 2 large eggs, one at a time. Add 2 teaspoons vanilla extract, 1/4 teaspoon almond extract (optional), and 1 teaspoon lemon zest (optional).
Finish the batter: Mix in 1/2 cup sour cream.
Add dry ingredients in two parts, alternating with 1/2 cup milk, beginning and ending with dry. Mix until just combined. Do not overmix.
Fill and bake: Divide batter evenly among liners (about two-thirds full).
Bake 18–22 minutes, until tops spring back and a toothpick comes out clean.
Cool: Let cupcakes cool in pan 5 minutes, then transfer to a rack to cool completely before frosting.
Make the buttercream: Beat 1 cup soft unsalted butter until pale and fluffy, 2–3 minutes. Gradually add 3–3 1/2 cups confectioners’ sugar with a pinch of salt. Add 2–4 tablespoons heavy cream as needed to reach a smooth, pipeable consistency.
Beat in 2 teaspoons vanilla extract. Taste and adjust salt/vanilla.
Pipe and decorate: Fill a piping bag fitted with a large star tip. Pipe rosettes or swirls.
Finish with edible pearls, a tiny piece of gold leaf, or a few dried petals. Keep it minimal for an elegant look.