Ingredients

FOR THE CRUMBLE

• 4 

  graham crackers

• 3/4 c. 

  rolled oats

• 1/3 c. 

  packed light brown sugar

• 3 tbsp. 

  all-purpose flour

• 6 tbsp. 

  cold butter, cubed

FOR THE MOUSSE

• 1 1/2 c. 

  heavy cream

• 1/4 c. 

  powdered sugar

• 1 c. 

  sweetened condensed milk

• 1/3 c. 

  freshly squeezed key lime juice

• 1 tsp. 

  pure vanilla extract

• Green food coloring (optional) 

• Key lime wedges, for garnish

Directions

• Directions

• • Step 1Preheat oven to 350°. In a food processor, pulse graham crackers into fine crumbs. In a medium bowl, combine crushed graham crackers, oats, brown sugar, and flour. Add butter and use your hands to cut into mixture until pea-sized and mixture starts to hold together. Spread mixture into an even layer on a baking sheet. Bake until golden and crisp, about 20 minutes, stirring halfway through. Let cool. 
  • Step 2Make mousse: In a large bowl, using a hand mixer (or in the bowl of a stand mixer fitted with the whisk attachment), beat cream and powdered sugar into stiff peaks. Remove about 1 cup of whipped cream to reserve for topping. 
  • Step 3In a medium bowl, combine condensed milk, lime juice, vanilla, and a small drop of food coloring, if using. Add to bowl of whipped cream. Gently fold in until just combined. 
  • Step 4Assemble: Add about ¼ cup of crumble to the bottom of 4 glasses. Top with two large spoonfuls of mousse, then repeat with another layer of crumble and mousse. 
  • Step 5Place reserved whipped cream in a piping bag fitted with a large closed star tip, and pipe onto mousse. Top with any remaining crumble and a lime wedge in each glass. 
  • Step 6Keep refrigerated until ready to serve.