Preheat the oven to 350°F (180°C). Grease the inside of an 8" or 9" round springform cheesecake pan with a bit of cold butter.

Combine crushed graham crackers, brown sugar, and salt in a large bowl. Give it a quick stir. Add melted butter and stir again.

Transfer the crumbs into the springform pan and press the crumbs halfway up the sides of the pan. Press the crumbs into the bottom of the pan with the bottom of a glass.

Place the springform pan onto a larger pan and bake for 8 minutes. Remove the pan from the oven and let it cool. Lower the temperature of the oven to 300°F (150°C).

Grind the poppy seeds roughly - I found that a clean coffee grinder works best for this. Alternatively, use a food processor or a mortar and pestle.

Combine ground poppy seeds, milk, 2 tablespoons sugar, and almond extract in a small saucepan. Cook on low heat, stirring frequently, until the milk is absorbed and it forms a thick paste.

In a large bowl or standmixer, combine 1 cup of sugar and grated lemon zest from two lemons. Rub the mixture in with your fingers until fragrant and moist. Stir in the cornstarch.

Add the softened cream cheese to the standmixer with the sugar. Mix with the paddle attachment until creamy, making sure to scrape down the sides of the bowl well.

Add the sour cream, vanilla extract, and salt. Measure out 3 tablespoons of freshly squeezed lemon juice and add it into the cheesecake batter. Mix well to combine, scraping down the bowl again.

Then, add the eggs one by one into the cheesecake batter, mixing after each egg is added just until the egg is incorporated. Make sure that you scrape the edges of the bowl every time you add an egg so that the batter is mixed evenly.

Divide the batter in half. Add yellow food coloring into one half (optional). Add the cooked poppy seeds into the other half and stir.

Pour the cheesecake batters into the crust, alternating colors. Reserve a few tablespoons of the poppy seed batter to spoon on top and use a toothpick to swirl it in.

To make the waterbath, fill a kettle up with water and set it to boil. You will need a large baking tray and a smaller baking pan that will fit the cheesecake springform pan. If you don't have a smaller baking pan, use an extra large piece of foil and wrap it around the bottom of the springform pan to prevent water from getting in the cheesecake. You can also use a crockpot bag as a barrier instead.

Place the baking pans into the oven, and pour boiling water into the outermost baking pan. Bake the cheesecake in the 300°F (150°C) preheated oven for 1 hour and 30 minutes. The cheesecake is ready when the edges are set and the inside is puffed but still jiggly. Turn the oven off and leave the cheesecake in the oven for 30 minutes.

Remove the cheesecake and let it cool at room temperature before refrigerating and letting it set in the fridge for at least 6 hours or overnight.

Combine chilled whipping cream, powdered sugar, and vanilla extract in a medium bowl or stand mixer. Whisk with a whisk attachment until medium peaks.

Add the sour cream (or yogurt) and whisk to stiff peaks.

Remove the cheesecake from the fridge. Take the springform sides off. Scoop heaping tablespoons of the whipped cream on top along the edge and use a smaller spoon to create indents in the middle of each scoop. Fill the indents with lemon curd. Sprinkle poppy seeds on top. Slice and serve when chilled.