• Preheat the oven to 350°F/175°C. Position rack to middle.
• Line a large baking sheet with parchment paper.
• In a large mixing bowl, sift together flour, cocoa powder, baking powder, espresso powder and salt. Set aside.
• In the bowl of a stand mixer fitted with the whisk attachment, whisk the eggs on medium-high speed until nice and frothy (about 3-4 minutes).
• Slowly add sugar. Continue to whisk until well combined and slightly thickened (about 2 minutes).
• Mix in the olive oil and vanilla extract until fully incorporated.
• Remove bowl from stand.
• Add the sifted dry ingredients and mix with a wooden spoon or rubber spatula until well combined. The dough will be stiff.
• Shaping the cookies:

  Using a churro maker with a star attachment: Pipe the dough into 4-inch strips and shape into S curves on the prepared baking sheet.

  Without a churros maker: Scoop dough with a medium-sized cookie scoop (approximately 2 tablespoons or 25 grams), roll into a rope, and shape into an S.
• Bake for 12–15 minutes, or until the cookies are just set around the edges. Do not overbake.
• Transfer cookies to a wire rack to cool completely before icing.

Chocolate Glaze

• In a small bowl, whisk the cocoa powder with the hot water until smooth and glossy. Let it sit for about 30 seconds to fully bloom the cocoa.
• Add the powdered sugar and vanilla, whisking until combined.
• Dip one side of each completely cooled cookie into the icing, let the excess drip off, and immediately sprinkle with a few chocolate jimmies on the dipped side only.
• Place on a wire rack and let the icing set.