Preheat oven to 350°F. Line an 8×8-inch baking pan with parchment, leaving an overhang for easy lifting.
In a bowl, whisk together flour, cocoa powder, sugar, baking powder, and salt.
Add melted butter, egg, and vanilla. Mix until a thick dough forms.
Press the dough evenly into the pan. Bake for 10–12 minutes, just until set.
Combine raspberry jam and lemon juice. Spread over the warm crust.
Sprinkle the raspberries evenly across the top.
Return the pan to the oven and bake for 15–18 minutes, until the jam is bubbling slightly around the edges.
Melt chocolate chips and coconut oil in the microwave in 20–30 second bursts, stirring until smooth. Drizzle over the cooled bars.
Let the bars cool completely before lifting out and slicing into squares.