Spread the almonds onto a baking tray; toast until they are golden brown and fragrant; about 5 minutes. Remove from baking tray and reserve.
Melt butter in a small saucepan placed over medium heat. Stir in brown sugar. Cook stirring until sugar has dissolved and mixture is bubbly. Remove from heat. Stir in vanilla and rolled oats. Press mixture into an 20 x 20cm baking tray. Bake in preheated oven until lightly browned and set; about 20 minutes.
Remove from oven and allow to cool slightly. Sprinkle chocolate chips over surface then let chocolate sit until melted; 2 to 3 minutes. Spread chocolate evenly over oatmeal squares.
Sprinkle warm chocolate with toasted almonds. Cut into squares when cool.