Dessert boards are a terrific option for busy cooks who love to entertain but are short on time. Just melt and whip the butter with sugar and seasonings, then let it cool to a spreading consistency. The rest is mere assembly: fruit, walnuts, and cookies, done.
Melt butter in a medium pot over medium-low heat. Stir in espresso powder and cook, stirring often, as butter foams and then begins to brown and smell nutty, about 5 minutes.
When golden brown, scrape into a medium bowl and chill until firm. Remove from refrigerator and let soften to room temperature, stirring occasionally.
Use a handheld mixer to beat butter until lighted, about 1 minute. Add powdered sugar, vanilla, and a pinch of salt and beat again until fluffy and whipped, about 3 minutes.
Spread whipped butter evenly over the surface of a cutting board. Sprinkle with walnuts, grapes, raspberries and strawberries. Serve with cookies, wafers and sliced brioche.