Gather all your ingredients and materials. You will need to be very attentive to prevent scorching, so you don't want to be shuffling around the kitchen once this is underway.

Line an 8" x 8" metal baking pan with aluminum foil, making sure the shiny side of the foil is facing up. Get a long-handled wooden spoon you can use to stir the candy when it is very hot. Do not use a plastic spoon; it will melt.

In a heavy-bottomed sauce pan, heat the butter over medium-high heat, first to melt, and then to boiling.

Add the water and bring back to the boil.

When the mixture is boiling, add sugar and salt.

Continue cooking over medium-high heat, stirring constantly with your wooden spoon. This will start to get very hot and you may want to use a pot-holder to protect your hand while you continuously stir the bubbling liquid. This will turn creamy-looking and be extremely hot, take care! Continue cooking and stirring until a candy thermometer reaches 308°F (hard-crack).

Quickly and carefully tip the hot mixture into the foil-lined pan. Spread out evenly if necessary using the wooden spoon.

Let cool for several hours. Once completely cooled, tip the toffee and aluminum foil, peel the foil away, and then break up the toffee. I put it between two sheets of parchment in a ziploc and smashed it with a rolling pin.

Note: cleaning a pot after making candy can seem impossible, but the easiest way to do it is to fill your pot with water and bring it to the boil. This will melt the stuck candy, and you can swirl your wooden spoon around in the boiling water to remove the cemented sugar from both implements at once!

Toss the wafers and salt into a food processor and pulse until fine.

Chop the butter into large chunks and add the chunks - cold or room temperature - to the food processor. [ A note: I have never known a recipe to tell you to make a crumb crust this way, but trust my skilled baker friend. It holds together better when cutting later. It will, naturally, also be delicious if you make it the usual way, by melting the butter and mixing that with the pulverized biscuits. ]

Pulverize the butter and biscuit mixture until it resembles fine bread crumbs.

Spread the crumb mixture into a 9-inch springform pan and press the mixture firmly and evenly, coming partway up the sides. You may want to get your hands slightly damp to make it easier. Try to avoid leaving a thicker part at the edge of the base of the pan, keep pressing and spreading it evenly.

Cover with plastic wrap and pop in the fridge until you are ready to fill. This will be fine overnight.

Preheat oven to 350°F and adjust oven rack to the middle of the oven.

Beat cream cheese in a stand mixer fitted with the paddle attachment (or with a handheld mixer) at mid-speed until fluffy. You will probably need to scrape down the sides and the paddle at least once.

Turn the mixer to low. Add the eggs one at a time, beating on low speed until incorporated. Scrape down the sides between adding each egg.

With the mixer still on low, add the vanilla and then the sugar, scraping the bowl between each addition. Mix until well incorporated.

Take your springform pan with the now-cold crumb crust out of the fridge and place it on a rimmed baking pan (to catch any spills and save your oven). Pour the filling into the crust.

Bake in the preheated oven for about 45 minutes, or until the edges of the cake are set but the middle is still slightly wobbly when gently shaken. Don't overbake!

Remove from oven and let cool completely. Once completely cool, you can top with the ganache or cover with plastic wrap and store in the fridge for a day or two.

In a small, clean, heavy-bottomed sauce pan, bring the cream to a boil. It should bubble and rise up in the pan.

While you are waiting for the cream to boil, chop your chocolate finely with a large serrated knife (like a bread knife). A serrated knife is less likely to slip on the chocolate and cause you injury. Do not skip this step, even if your chocolate is already in small chunks or callets! You want it to be fine and consistent so it will melt easily and evenly.

Place finely chopped chocolate in a heat-proof bowl.

Once at boiling, pour the cream carefully over the chocolate. Tap the bowl gently against the counter to help settle the chocolate.

Wait one minute. Breathe in the chocolatey goodness.

Using a rubber spatula, gently stir the chocolate, starting from the inside and moving gently out. Stir gently for two minutes, trying not to incorporate too much air but fully emulsifying the chocolate into the cream. This is the best part, you'll want to dive in.

Once fully incorporated, allow to cool to 70°F before trying to spread on the cake. You can give it an occasional stir while it cools.

I found it easier to spread the ganache and sprinkle the toffee while the cake was still in the springform, because it makes fridge storage so much easier when your cake has sides! It would probably be a little neater if you did it after you take the cake out of the springpan, but up to you.

Also, if you've done things in a different order, no worries! Just make sure everything is nice and cool before you start assembling. Hot cake, hot ganache, or hot toffee will absolutely result in a big mess.

Evenly spread the cooled ganache on the cooled cheesecake using an offset spatula.

Sprinkle with chunks of toffee to your taste; I did not use the entire recipe's worth of toffee by a long shot.