Most of this menu can be prepared in advance. The bruschetta bar serves 12; you'll probably have leftover toppings.
• 4 days ahead (or up to 3 months before Halloween): Start infusing the vodka.
• 2 days before the party: Make the cookies.
• 1 day in advance: Prepare toppings for the bruschetta bar.
• 4 hours before guests arrive: Slice and toast baguettes.
• 1 hour before guests arrive: Set out refrigerated mushroom pâté and sweet onions and peppers (keep chicken-cress salad refrigerated until ready to serve), and prepare spinach and pumpkin salad. Start cider; as it's heating, plate cookies and set out toasted baguettes.
Arrange sweet onions and peppers, chicken-cress salad, and mushroom pâté (recipes follow), plus bowls of peanut butter, whipped cream cheese, and jam, on buffet alongside toasted baguette slices (you'll need about 3 baguettes).