In the bowl of a stand mixer (or large mixing bowl) beat the melted butter, sugar, espresso powder and vanilla. Beat in the eggs, one at a time, until thoroughly blended.
In a medium bowl add flour, cocoa powder, and salt. Whisk until no lumps of coca power remain. With mixer on low speed, gradually add flour/cocoa powder mixture into the butter/egg mixture until blended. Don’t over mix. Stir in the chocolate morsels. Spread the batter evenly over the pretzel crust.
Bake for 30 to 35 minutes, until top is crackly and an inserted toothpick comes out mostly clean (some batter n the bottom is fine). Remove, and set pan on a wire rack. Cool pan fully before cutting and drizzling toppings.
Make and drizzle topping: Note: Make sure brownies are fully cool before topping.
Cut brownies and lay them close together on a sheet of parchment or foil.
In a small glass bowl, add caramel candies. Place bowl in microwave set on half power setting, Heat in 10-15 second bursts, stirring between each one until candy is fully melted. Dip a spoon in and drizzle all over brownies. Working quickly while caramel is hot, gently press pretzels into caramel, one for each brownie.
In a separate bowl, repeat process with chocolate chips. Drizzle melted chocolate over brownies (of drizzling with the spoon doesn’t work, add melted chocolate to a zip top bag and snip one corner off). Sprinkle with just a little flaky sea salt and serve.