Preheat oven to 350°F.
Butter a 10×15-inch rimmed baking pan.
Cream butter and sugar until light and fluffy. Beat in eggs and vanilla. Combine flour, cocoa, and salt.
Fold dry ingredients into creamed mixture by hand to moisten dry ingredients and avoid dusting; then mix until well blended. Spread mixture in prepared pan.
Sprinkle raspberries evenly over batter and gently press them into batter. Sprinkle nuts evenly over the top.
Bake 20-25 minutes. Cool and cut into squares.