berry delicious rhubarb crisp

Ingredients For berry delicious rhubarb crisp

• 1 c

  all-purpose flour
• 1 c

  packed brown sugar
• 3/4 c

  old-fashioned oats
• 1/2 c

  cup butter, melted
• 1 1/ tsp

  vanilla extract, divided
• 1 tsp

  ground cinnamon
• 1 1/2 c

  diced fresh or frozen rhubarb
• 1 1/2 c

  sliced fresh strawberries
• 1 1/2 c

  fresh blackberries
• 1/2 c

  sugar
• 1 Tbsp

  cornstarch
• 1/2 c

  cold water
• vanilla ice cream