Prep the Pan: Preheat oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper, leaving overhang for easy lifting. Lightly spray with nonstick cooking spray.
Make the Cookie Base: In a large mixing bowl, cream butter and brown sugar until smooth. Beat in vanilla and egg.
Add Dry Ingredients: Stir in flour, chocolate graham crumbs, baking powder, and salt until combined. Fold in chocolate chips.
Bake the Crust: Press dough evenly into prepared pan and bake for 5 minutes.
Add the Layers: Remove from oven and sprinkle mini chocolate chips (reserving a little for garnish), coconut, and sliced almonds over the crust.
Pour the Sweetness: Drizzle sweetened condensed milk evenly over the top, then sprinkle with reserved mini chips.
Finish Baking: Return to oven for 25–30 minutes, tenting loosely with foil halfway to prevent over-browning. Bars should be set and lightly golden.
Cool & Slice: Let cool for 30 minutes at room temperature, then refrigerate until completely chilled before cutting into 9–12 squares.
