Prep: 1. Let butter come to room temperature. 2. Preheat oven to 350. Grease muffin tin. 2. Zest lemon and slice apricots. Make: 1. Whisk flour, baking powder, and salt in a medium bowl. 2. Using an electric mixer, beat butter and sugar in another medium bowl, until light and fluffy, about 2 minutes. Add egg, lemon zest, and vanilla and beat until combined. 3. With mixer on low, add flour mixture to butter mixture in 3 additions alternating with milk in 2 additions, beginning and ending with dry ingredients. 4. Fill muffin tins 1/3 of the way full and top with 1-2 apricot slices and sprinkle with raw sugar. 5. Bake until cakes are golden and a tester inserted into the center comes out clean, 20-25 minutes. 6. Let cool.