Preheat oven to 300 degrees F. In a large mixing bowl, toss together oats and sliced almonds; set aside.

In a medium saucepan, combine brown sugar, honey, water, cinnamon, and salt. Bring mixture to a boil, stirring frequently. Once mixture reaches a boil, allow to boil for 1 minute, whisking constantly.

Remove from heat, stir in vanilla and baking soda, and whisk until mixture is foamy. Carefully pour hot sugar mixture over oat mixture and toss to evenly coat.

Spread mixture into an even layer on a silicone baking mat or parchment paper-lined 18 by 13-inch rimmed baking sheet.

Bake in preheated oven for about 36-40 minutes until lightly golden brown, removing from oven and tossing twice during baking.

Remove from oven, allow to cool completely, then break into clusters. Store in an airtight container.