Line an 8x8-inch baking pan with parchment paper, leaving an overhang on two opposite sides to create a sling for lifting the fudge out later. If your parchment is thin, lightly mist it with nonstick cooking spray.

Roughly chop 2 cups of frosted animal cookies. Aim for a mix of small bits and slightly larger chunks so they stay visible and add texture without making the fudge hard to cut. Set aside the additional whole frosted animal cookies for topping.

In a medium saucepan, combine the white chocolate chips, sweetened condensed milk, and unsalted butter. Set the pan over low heat and stir often with a heat-safe spatula, scraping the bottom and sides, until the mixture is mostly melted and smooth. Keep the heat low to prevent the white chocolate from overheating and seizing.

Remove the saucepan from the heat as soon as the white chocolate mixture is melted and glossy. Stir in the vanilla extract, almond extract (if using), and a pinch of fine sea salt until fully combined. The mixture should be thick but still pourable. If it seems too stiff, warm it gently over low heat for another 15–20 seconds, stirring constantly.

Let the fudge base cool for about 1 minute so it is warm but not scorching hot. Gently fold in the chopped frosted animal cookies and 1–2 tablespoons of the rainbow sprinkles. Stir just until evenly distributed, being careful not to crush the cookies into fine crumbs.

Pour or scrape the circus animal cookie fudge mixture into the prepared 8x8-inch pan. Use a spatula to spread it evenly into the corners and smooth the top. The mixture will be thick; press and smooth it as needed.

Press the reserved whole frosted animal cookies gently into the top of the fudge, spacing them out evenly. Sprinkle the remaining rainbow sprinkles over the surface, focusing on any bare spots.

Refrigerate the fudge for 1–2 hours, or until fully set. If your refrigerator is crowded, allow up to 3 hours. The center should feel firm when gently pressed with a fingertip.

Use the parchment sling to lift the chilled fudge out of the pan and onto a cutting board. With a sharp knife, cut into about 36 small squares (or 25 larger pieces if preferred). Wipe the knife clean with a warm, damp cloth between cuts for neat edges. Serve chilled or at cool room temperature.