1. Preheat oven to 325°. Butter a 9- by 13-in. baking pan. In a large bowl with a mixer on medium speed, beat butter and granulated sugar until fluffy. Beat in eggs, salt, vanilla, yogurt, milk, and lemon curd until mostly blended.
2. Add flour, baking soda, and baking powder to bowl and beat until smooth. Spread half of batter in pan and scatter half of raspberries on top. Gently spread remaining batter over berries. Scatter remaining berries on top.
3. Bake until a toothpick inserted in center comes out clean, about 1 hour; if cake begins to brown too quickly, tent with foil. Let cake cool about 1 hour, then dust lightly with powdered sugar.
*Find with jams at grocery stores.